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-rw-r--r--crypto/Readme.html1
-rw-r--r--crypto/crypto.csproj30
-rw-r--r--crypto/src/asn1/cryptopro/ECGOST3410NamedCurves.cs45
-rw-r--r--crypto/src/asn1/x9/X962NamedCurves.cs6
-rw-r--r--crypto/src/asn1/x9/X9Curve.cs76
-rw-r--r--crypto/src/asn1/x9/X9ECParameters.cs27
-rw-r--r--crypto/src/asn1/x9/X9FieldElement.cs2
-rw-r--r--crypto/src/crypto/agreement/ECDHBasicAgreement.cs20
-rw-r--r--crypto/src/crypto/agreement/ECDHCBasicAgreement.cs14
-rw-r--r--crypto/src/crypto/agreement/ECMqvBasicAgreement.cs13
-rw-r--r--crypto/src/crypto/agreement/SM2KeyExchange.cs6
-rw-r--r--crypto/src/crypto/engines/Cast5Engine.cs2
-rw-r--r--crypto/src/crypto/engines/IdeaEngine.cs16
-rw-r--r--crypto/src/crypto/parameters/ECDomainParameters.cs41
-rw-r--r--crypto/src/crypto/parameters/ECPublicKeyParameters.cs21
-rw-r--r--crypto/src/math/ec/ECAlgorithms.cs31
-rw-r--r--crypto/src/math/ec/ECCurve.cs73
-rw-r--r--crypto/src/math/ec/ECFieldElement.cs94
-rw-r--r--crypto/src/math/ec/ECPoint.cs170
-rw-r--r--crypto/src/math/ec/custom/djb/Curve25519FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP128R1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP160R1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP160R2FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP192K1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP192R1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP224K1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP224R1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP256K1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP256R1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP384R1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecP521R1FieldElement.cs2
-rw-r--r--crypto/src/math/ec/custom/sec/SecT113FieldElement.cs7
-rw-r--r--crypto/src/math/ec/custom/sec/SecT131FieldElement.cs7
-rw-r--r--crypto/src/math/ec/custom/sec/SecT163FieldElement.cs7
-rw-r--r--crypto/src/math/ec/custom/sec/SecT193FieldElement.cs7
-rw-r--r--crypto/src/math/ec/custom/sec/SecT233FieldElement.cs7
-rw-r--r--crypto/src/math/ec/custom/sec/SecT239FieldElement.cs7
-rw-r--r--crypto/src/math/ec/custom/sec/SecT283FieldElement.cs7
-rw-r--r--crypto/src/math/ec/custom/sec/SecT409FieldElement.cs7
-rw-r--r--crypto/src/math/ec/custom/sec/SecT571FieldElement.cs7
-rw-r--r--crypto/src/math/ec/multiplier/AbstractECMultiplier.cs7
-rw-r--r--crypto/src/math/ec/multiplier/FixedPointCombMultiplier.cs6
-rw-r--r--crypto/src/math/ec/multiplier/FixedPointPreCompInfo.cs14
-rw-r--r--crypto/src/math/ec/multiplier/FixedPointUtilities.cs63
-rw-r--r--crypto/src/math/ec/multiplier/IPreCompCallback.cs9
-rw-r--r--crypto/src/math/ec/multiplier/ValidityPreCompInfo.cs44
-rw-r--r--crypto/src/math/ec/multiplier/WNafUtilities.cs311
-rw-r--r--crypto/src/math/ec/multiplier/WTauNafMultiplier.cs47
-rw-r--r--crypto/src/math/ec/rfc7748/X25519.cs4
-rw-r--r--crypto/src/math/ec/rfc7748/X25519Field.cs147
-rw-r--r--crypto/src/math/ec/rfc7748/X448.cs8
-rw-r--r--crypto/src/math/ec/rfc7748/X448Field.cs123
-rw-r--r--crypto/src/math/ec/rfc8032/Ed25519.cs937
-rw-r--r--crypto/src/math/ec/rfc8032/Ed448.cs1067
-rw-r--r--crypto/src/math/raw/Interleave.cs71
-rw-r--r--crypto/src/math/raw/Nat.cs85
-rw-r--r--crypto/src/openpgp/PgpUtilities.cs21
-rw-r--r--crypto/test/src/crypto/test/ECGOST3410Test.cs10
-rw-r--r--crypto/test/src/crypto/test/ECIESTest.cs12
-rw-r--r--crypto/test/src/crypto/test/ECNRTest.cs2
-rw-r--r--crypto/test/src/crypto/test/ECTest.cs55
-rw-r--r--crypto/test/src/crypto/test/SM2EngineTest.cs7
-rw-r--r--crypto/test/src/crypto/test/SM2KeyExchangeTest.cs7
-rw-r--r--crypto/test/src/crypto/test/SM2SignerTest.cs6
-rw-r--r--crypto/test/src/math/ec/rfc8032/test/Ed25519Test.cs231
-rw-r--r--crypto/test/src/math/ec/rfc8032/test/Ed448Test.cs400
-rw-r--r--crypto/test/src/math/ec/test/ECPointTest.cs18
-rw-r--r--crypto/test/src/security/test/TestEncodings.cs31
-rw-r--r--crypto/test/src/security/test/TestSignerUtil.cs16
-rw-r--r--crypto/test/src/test/CertTest.cs25
-rw-r--r--crypto/test/src/test/DHTest.cs33
-rw-r--r--crypto/test/src/test/DSATest.cs66
-rw-r--r--crypto/test/src/test/GOST3410Test.cs20
-rw-r--r--crypto/test/src/test/IESTest.cs11
-rw-r--r--crypto/test/src/test/MqvTest.cs21
-rw-r--r--crypto/test/src/test/PKCS10CertRequestTest.cs25
-rw-r--r--crypto/test/src/x509/test/TestCertificateGen.cs21
78 files changed, 4032 insertions, 726 deletions
diff --git a/crypto/Readme.html b/crypto/Readme.html
index c05560d93..9f4705f00 100644
--- a/crypto/Readme.html
+++ b/crypto/Readme.html
@@ -301,6 +301,7 @@ We state, where EC MQV has not otherwise been disabled or removed:
             <li>Further work has been done on improving SHA-3 performance.</li>
             <li>EC key generation and signing now use cache-timing resistant table lookups.</li>
             <li>RFC 7748: Added low-level implementations of X25519 and X448.</li>
+            <li>RFC 8032: Added low-level implementations of Ed25519 and Ed448.</li>
         </ul>
         <h5>Additional Notes</h5>
         <ul>
diff --git a/crypto/crypto.csproj b/crypto/crypto.csproj
index d0afb9f14..7cd8de821 100644
--- a/crypto/crypto.csproj
+++ b/crypto/crypto.csproj
@@ -6154,6 +6154,11 @@
                     BuildAction = "Compile"
                 />
                 <File
+                    RelPath = "src\math\ec\multiplier\IPreCompCallback.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
                     RelPath = "src\math\ec\multiplier\MixedNafR2LMultiplier.cs"
                     SubType = "Code"
                     BuildAction = "Compile"
@@ -6184,6 +6189,11 @@
                     BuildAction = "Compile"
                 />
                 <File
+                    RelPath = "src\math\ec\multiplier\ValidityPreCompInfo.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
                     RelPath = "src\math\ec\multiplier\WNafL2RMultiplier.cs"
                     SubType = "Code"
                     BuildAction = "Compile"
@@ -6239,6 +6249,16 @@
                     BuildAction = "Compile"
                 />
                 <File
+                    RelPath = "src\math\ec\rfc8032\Ed25519.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "src\math\ec\rfc8032\Ed448.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
                     RelPath = "src\math\field\FiniteFields.cs"
                     SubType = "Code"
                     BuildAction = "Compile"
@@ -12340,6 +12360,16 @@
                     BuildAction = "Compile"
                 />
                 <File
+                    RelPath = "test\src\math\ec\rfc8032\test\Ed25519Test.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "test\src\math\ec\rfc8032\test\Ed448Test.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
                     RelPath = "test\src\math\ec\test\AllTests.cs"
                     SubType = "Code"
                     BuildAction = "Compile"
diff --git a/crypto/src/asn1/cryptopro/ECGOST3410NamedCurves.cs b/crypto/src/asn1/cryptopro/ECGOST3410NamedCurves.cs
index 9c366503d..b61da6b57 100644
--- a/crypto/src/asn1/cryptopro/ECGOST3410NamedCurves.cs
+++ b/crypto/src/asn1/cryptopro/ECGOST3410NamedCurves.cs
@@ -32,15 +32,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("115792089237316195423570985008687907853269984665640564039457584007913129639316"), // a
                 new BigInteger("166"), // b
-                mod_q,
-                BigInteger.One);
+                mod_q, BigInteger.One);
 
             ECDomainParameters ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("1"), // x
                     new BigInteger("64033881142927202683649881450433473985931760268884941288852745803908878638612")), // y
-                mod_q);
+                mod_q, BigInteger.One);
 
             parameters[CryptoProObjectIdentifiers.GostR3410x2001CryptoProA] = ecParams;
 
@@ -51,15 +50,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("115792089237316195423570985008687907853269984665640564039457584007913129639316"),
                 new BigInteger("166"),
-                mod_q,
-                BigInteger.One);
+                mod_q, BigInteger.One);
 
             ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("1"), // x
                     new BigInteger("64033881142927202683649881450433473985931760268884941288852745803908878638612")), // y
-                mod_q);
+                mod_q, BigInteger.One);
 
             parameters[CryptoProObjectIdentifiers.GostR3410x2001CryptoProXchA] = ecParams;
 
@@ -70,15 +68,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("57896044618658097711785492504343953926634992332820282019728792003956564823190"), // a
                 new BigInteger("28091019353058090096996979000309560759124368558014865957655842872397301267595"), // b
-                mod_q,
-                BigInteger.One);
+                mod_q, BigInteger.One);
 
             ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("1"), // x
                     new BigInteger("28792665814854611296992347458380284135028636778229113005756334730996303888124")), // y
-                mod_q); // q
+                mod_q, BigInteger.One);
 
             parameters[CryptoProObjectIdentifiers.GostR3410x2001CryptoProB] = ecParams;
 
@@ -89,15 +86,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("70390085352083305199547718019018437841079516630045180471284346843705633502616"),
                 new BigInteger("32858"),
-                mod_q,
-                BigInteger.One);
+                mod_q, BigInteger.One);
 
             ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("0"),
                     new BigInteger("29818893917731240733471273240314769927240550812383695689146495261604565990247")),
-                mod_q);
+                mod_q, BigInteger.One);
 
             parameters[CryptoProObjectIdentifiers.GostR3410x2001CryptoProXchB] = ecParams;
 
@@ -107,15 +103,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("70390085352083305199547718019018437841079516630045180471284346843705633502616"), // a
                 new BigInteger("32858"), // b
-                mod_q,
-                BigInteger.One);
+                mod_q, BigInteger.One);
 
             ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("0"), // x
                     new BigInteger("29818893917731240733471273240314769927240550812383695689146495261604565990247")), // y
-                mod_q); // q
+                mod_q, BigInteger.One);
 
             parameters[CryptoProObjectIdentifiers.GostR3410x2001CryptoProC] = ecParams;
 
@@ -126,15 +121,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("115792089237316195423570985008687907853269984665640564039457584007913129639316"), // a
                 new BigInteger("166"), // b
-                mod_q,
-                BigInteger.One);
+                mod_q, BigInteger.One);
 
             ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("1"), // x
                     new BigInteger("64033881142927202683649881450433473985931760268884941288852745803908878638612")), // y
-                mod_q); // q
+                mod_q, BigInteger.One);
 
             parameters[RosstandartObjectIdentifiers.id_tc26_gost_3410_12_256_paramSetA] = ecParams;
 
@@ -144,15 +138,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFDC4",16), // a
                 new BigInteger("E8C2505DEDFC86DDC1BD0B2B6667F1DA34B82574761CB0E879BD081CFD0B6265EE3CB090F30D27614CB4574010DA90DD862EF9D4EBEE4761503190785A71C760",16), // b
-                mod_q,
-                BigInteger.One);
+                mod_q, BigInteger.One);
 
             ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000003"), // x
                     new BigInteger("7503CFE87A836AE3A61B8816E25450E6CE5E1C93ACF1ABC1778064FDCBEFA921DF1626BE4FD036E93D75E6A50E3A41E98028FE5FC235F5B889A589CB5215F2A4",16)), // y
-                mod_q); // q
+                mod_q, BigInteger.One);
 
             parameters[RosstandartObjectIdentifiers.id_tc26_gost_3410_12_512_paramSetA] = ecParams;
 
@@ -162,15 +155,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("8000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000006C",16), // a
                 new BigInteger("687D1B459DC841457E3E06CF6F5E2517B97C7D614AF138BCBF85DC806C4B289F3E965D2DB1416D217F8B276FAD1AB69C50F78BEE1FA3106EFB8CCBC7C5140116",16), // b
-                mod_q,
-                BigInteger.One);
+                mod_q, BigInteger.One);
 
             ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000002"), // x
                     new BigInteger("1A8F7EDA389B094C2C071E3647A8940F3C123B697578C213BE6DD9E6C8EC7335DCB228FD1EDF4A39152CBCAAF8C0398828041055F94CEEEC7E21340780FE41BD",16)), // y
-                mod_q); // q
+                mod_q, BigInteger.One);
 
             parameters[RosstandartObjectIdentifiers.id_tc26_gost_3410_12_512_paramSetB] = ecParams;
 
@@ -180,15 +172,14 @@ namespace Org.BouncyCastle.Asn1.CryptoPro
                 mod_p, // p
                 new BigInteger("DC9203E514A721875485A529D2C722FB187BC8980EB866644DE41C68E143064546E861C0E2C9EDD92ADE71F46FCF50FF2AD97F951FDA9F2A2EB6546F39689BD3",16), // a
                 new BigInteger("B4C4EE28CEBC6C2C8AC12952CF37F16AC7EFB6A9F69F4B57FFDA2E4F0DE5ADE038CBC2FFF719D2C18DE0284B8BFEF3B52B8CC7A5F5BF0A3C8D2319A5312557E1",16), // b
-                mod_q,
-                BigInteger.One);
+                mod_q, BigInteger.One);
 
             ecParams = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("E2E31EDFC23DE7BDEBE241CE593EF5DE2295B7A9CBAEF021D385F7074CEA043AA27272A7AE602BF2A7B9033DB9ED3610C6FB85487EAE97AAC5BC7928C1950148", 16), // x
                     new BigInteger("F5CE40D95B5EB899ABBCCFF5911CB8577939804D6527378B8C108C3D2090FF9BE18E2D33E3021ED2EF32D85822423B6304F726AA854BAE07D0396E9A9ADDC40F",16)), // y
-                mod_q); // q
+                mod_q, BigInteger.One);
 
             parameters[RosstandartObjectIdentifiers.id_tc26_gost_3410_12_512_paramSetC] = ecParams;
 
diff --git a/crypto/src/asn1/x9/X962NamedCurves.cs b/crypto/src/asn1/x9/X962NamedCurves.cs
index 14f7f818a..1609774f1 100644
--- a/crypto/src/asn1/x9/X962NamedCurves.cs
+++ b/crypto/src/asn1/x9/X962NamedCurves.cs
@@ -31,7 +31,7 @@ namespace Org.BouncyCastle.Asn1.X9
                 BigInteger h = BigInteger.One;
 
                 ECCurve cFp192v1 = new FpCurve(
-                    new BigInteger("6277101735386680763835789423207666416083908700390324961279"),
+                    new BigInteger("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFFFFFFFFFF", 16),
                     new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16),
                     new BigInteger("64210519e59c80e70fa7e9ab72243049feb8deecc146b9b1", 16),
                     n, h);
@@ -58,7 +58,7 @@ namespace Org.BouncyCastle.Asn1.X9
                 BigInteger h = BigInteger.One;
 
                 ECCurve cFp192v2 = new FpCurve(
-                    new BigInteger("6277101735386680763835789423207666416083908700390324961279"),
+                    new BigInteger("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFFFFFFFFFF", 16),
                     new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16),
                     new BigInteger("cc22d6dfb95c6b25e49c0d6364a4e5980c393aa21668d953", 16),
                     n, h);
@@ -85,7 +85,7 @@ namespace Org.BouncyCastle.Asn1.X9
                 BigInteger h = BigInteger.One;
 
                 ECCurve cFp192v3 = new FpCurve(
-                    new BigInteger("6277101735386680763835789423207666416083908700390324961279"),
+                    new BigInteger("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFFFFFFFFFF", 16),
                     new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16),
                     new BigInteger("22123dc2395a05caa7423daeccc94760a7d462256bd56916", 16),
                     n, h);
diff --git a/crypto/src/asn1/x9/X9Curve.cs b/crypto/src/asn1/x9/X9Curve.cs
index f05a946c2..eab94def8 100644
--- a/crypto/src/asn1/x9/X9Curve.cs
+++ b/crypto/src/asn1/x9/X9Curve.cs
@@ -47,9 +47,19 @@ namespace Org.BouncyCastle.Asn1.X9
             }
         }
 
+        [Obsolete("Use constructor including order/cofactor")]
         public X9Curve(
             X9FieldID		fieldID,
             Asn1Sequence	seq)
+            : this(fieldID, null, null, seq)
+        {
+        }
+
+        public X9Curve(
+            X9FieldID		fieldID,
+            BigInteger      order,
+            BigInteger      cofactor,
+            Asn1Sequence	seq)
         {
             if (fieldID == null)
                 throw new ArgumentNullException("fieldID");
@@ -60,47 +70,47 @@ namespace Org.BouncyCastle.Asn1.X9
 
             if (fieldIdentifier.Equals(X9ObjectIdentifiers.PrimeField))
             {
-                BigInteger q = ((DerInteger) fieldID.Parameters).Value;
-                X9FieldElement x9A = new X9FieldElement(q, (Asn1OctetString) seq[0]);
-                X9FieldElement x9B = new X9FieldElement(q, (Asn1OctetString) seq[1]);
-                curve = new FpCurve(q, x9A.Value.ToBigInteger(), x9B.Value.ToBigInteger());
+                BigInteger p = ((DerInteger)fieldID.Parameters).Value;
+                BigInteger A = new BigInteger(1, Asn1OctetString.GetInstance(seq[0]).GetOctets());
+                BigInteger B = new BigInteger(1, Asn1OctetString.GetInstance(seq[1]).GetOctets());
+                curve = new FpCurve(p, A, B, order, cofactor);
             }
-            else
+            else if (fieldIdentifier.Equals(X9ObjectIdentifiers.CharacteristicTwoField)) 
             {
-                if (fieldIdentifier.Equals(X9ObjectIdentifiers.CharacteristicTwoField)) 
+                // Characteristic two field
+                DerSequence parameters = (DerSequence)fieldID.Parameters;
+                int m = ((DerInteger)parameters[0]).Value.IntValue;
+                DerObjectIdentifier representation
+                    = (DerObjectIdentifier)parameters[1];
+
+                int k1 = 0;
+                int k2 = 0;
+                int k3 = 0;
+                if (representation.Equals(X9ObjectIdentifiers.TPBasis)) 
                 {
-                    // Characteristic two field
-                    DerSequence parameters = (DerSequence)fieldID.Parameters;
-                    int m = ((DerInteger)parameters[0]).Value.IntValue;
-                    DerObjectIdentifier representation
-                        = (DerObjectIdentifier)parameters[1];
-
-                    int k1 = 0;
-                    int k2 = 0;
-                    int k3 = 0;
-                    if (representation.Equals(X9ObjectIdentifiers.TPBasis)) 
-                    {
-                        // Trinomial basis representation
-                        k1 = ((DerInteger)parameters[2]).Value.IntValue;
-                    }
-                    else 
-                    {
-                        // Pentanomial basis representation
-                        DerSequence pentanomial = (DerSequence) parameters[2];
-                        k1 = ((DerInteger) pentanomial[0]).Value.IntValue;
-                        k2 = ((DerInteger) pentanomial[1]).Value.IntValue;
-                        k3 = ((DerInteger) pentanomial[2]).Value.IntValue;
-                    }
-                    X9FieldElement x9A = new X9FieldElement(m, k1, k2, k3, (Asn1OctetString)seq[0]);
-                    X9FieldElement x9B = new X9FieldElement(m, k1, k2, k3, (Asn1OctetString)seq[1]);
-                    // TODO Is it possible to get the order (n) and cofactor(h) too?
-                    curve = new F2mCurve(m, k1, k2, k3, x9A.Value.ToBigInteger(), x9B.Value.ToBigInteger());
+                    // Trinomial basis representation
+                    k1 = ((DerInteger)parameters[2]).Value.IntValue;
                 }
+                else 
+                {
+                    // Pentanomial basis representation
+                    DerSequence pentanomial = (DerSequence) parameters[2];
+                    k1 = ((DerInteger) pentanomial[0]).Value.IntValue;
+                    k2 = ((DerInteger) pentanomial[1]).Value.IntValue;
+                    k3 = ((DerInteger) pentanomial[2]).Value.IntValue;
+                }
+                BigInteger A = new BigInteger(1, Asn1OctetString.GetInstance(seq[0]).GetOctets());
+                BigInteger B = new BigInteger(1, Asn1OctetString.GetInstance(seq[1]).GetOctets());
+                curve = new F2mCurve(m, k1, k2, k3, A, B, order, cofactor);
+            }
+            else
+            {
+                throw new ArgumentException("This type of ECCurve is not implemented");
             }
 
             if (seq.Count == 3)
             {
-                seed = ((DerBitString) seq[2]).GetBytes();
+                seed = ((DerBitString)seq[2]).GetBytes();
             }
         }
 
diff --git a/crypto/src/asn1/x9/X9ECParameters.cs b/crypto/src/asn1/x9/X9ECParameters.cs
index 0fa343768..e1b29ca13 100644
--- a/crypto/src/asn1/x9/X9ECParameters.cs
+++ b/crypto/src/asn1/x9/X9ECParameters.cs
@@ -23,29 +23,32 @@ namespace Org.BouncyCastle.Asn1.X9
 		public static X9ECParameters GetInstance(Object obj)
 		{
 			if (obj is X9ECParameters)
-			{
 				return (X9ECParameters)obj;
-			}
 
-			if (obj != null)
-			{
+            if (obj != null)
 				return new X9ECParameters(Asn1Sequence.GetInstance(obj));
-			}
 
-			return null;
+            return null;
 		}
 
         public X9ECParameters(
             Asn1Sequence seq)
         {
             if (!(seq[0] is DerInteger)
-               || !((DerInteger) seq[0]).Value.Equals(BigInteger.One))
+                || !((DerInteger)seq[0]).Value.Equals(BigInteger.One))
             {
                 throw new ArgumentException("bad version in X9ECParameters");
             }
 
+            this.n = ((DerInteger)seq[4]).Value;
+
+            if (seq.Count == 6)
+            {
+                this.h = ((DerInteger)seq[5]).Value;
+            }
+
             X9Curve x9c = new X9Curve(
-                X9FieldID.GetInstance(seq[1]),
+                X9FieldID.GetInstance(seq[1]), n, h,
                 Asn1Sequence.GetInstance(seq[2]));
 
             this.curve = x9c.Curve;
@@ -53,20 +56,14 @@ namespace Org.BouncyCastle.Asn1.X9
 
             if (p is X9ECPoint)
             {
-                this.g = ((X9ECPoint)p);
+                this.g = (X9ECPoint)p;
             }
             else
             {
                 this.g = new X9ECPoint(curve, (Asn1OctetString)p);
             }
 
-            this.n = ((DerInteger)seq[4]).Value;
             this.seed = x9c.GetSeed();
-
-            if (seq.Count == 6)
-            {
-                this.h = ((DerInteger)seq[5]).Value;
-            }
         }
 
         public X9ECParameters(
diff --git a/crypto/src/asn1/x9/X9FieldElement.cs b/crypto/src/asn1/x9/X9FieldElement.cs
index 94bd96b24..222b4cfc8 100644
--- a/crypto/src/asn1/x9/X9FieldElement.cs
+++ b/crypto/src/asn1/x9/X9FieldElement.cs
@@ -19,6 +19,7 @@ namespace Org.BouncyCastle.Asn1.X9
             this.f = f;
         }
 
+        [Obsolete("Will be removed")]
         public X9FieldElement(
             BigInteger		p,
             Asn1OctetString	s)
@@ -26,6 +27,7 @@ namespace Org.BouncyCastle.Asn1.X9
         {
         }
 
+        [Obsolete("Will be removed")]
         public X9FieldElement(
             int				m,
             int				k1,
diff --git a/crypto/src/crypto/agreement/ECDHBasicAgreement.cs b/crypto/src/crypto/agreement/ECDHBasicAgreement.cs
index ca7b3fa3f..1358db0cf 100644
--- a/crypto/src/crypto/agreement/ECDHBasicAgreement.cs
+++ b/crypto/src/crypto/agreement/ECDHBasicAgreement.cs
@@ -45,12 +45,26 @@ namespace Org.BouncyCastle.Crypto.Agreement
         public virtual BigInteger CalculateAgreement(
             ICipherParameters pubKey)
         {
-            ECPublicKeyParameters pub = (ECPublicKeyParameters) pubKey;
-            if (!pub.Parameters.Equals(privKey.Parameters))
+            ECPublicKeyParameters pub = (ECPublicKeyParameters)pubKey;
+            ECDomainParameters dp = privKey.Parameters;
+            if (!dp.Equals(pub.Parameters))
                 throw new InvalidOperationException("ECDH public key has wrong domain parameters");
 
-            ECPoint P = pub.Q.Multiply(privKey.D).Normalize();
+            BigInteger d = privKey.D;
 
+            // Always perform calculations on the exact curve specified by our private key's parameters
+            ECPoint Q = ECAlgorithms.CleanPoint(dp.Curve, pub.Q);
+            if (Q.IsInfinity)
+                throw new InvalidOperationException("Infinity is not a valid public key for ECDH");
+
+            BigInteger h = dp.H;
+            if (!h.Equals(BigInteger.One))
+            {
+                d = dp.HInv.Multiply(d).Mod(dp.N);
+                Q = ECAlgorithms.ReferenceMultiply(Q, h);
+            }
+
+            ECPoint P = Q.Multiply(d).Normalize();
             if (P.IsInfinity)
                 throw new InvalidOperationException("Infinity is not a valid agreement value for ECDH");
 
diff --git a/crypto/src/crypto/agreement/ECDHCBasicAgreement.cs b/crypto/src/crypto/agreement/ECDHCBasicAgreement.cs
index 1c9ae45f9..f0b5d1e02 100644
--- a/crypto/src/crypto/agreement/ECDHCBasicAgreement.cs
+++ b/crypto/src/crypto/agreement/ECDHCBasicAgreement.cs
@@ -50,15 +50,19 @@ namespace Org.BouncyCastle.Crypto.Agreement
         public virtual BigInteger CalculateAgreement(
             ICipherParameters pubKey)
         {
-            ECPublicKeyParameters pub = (ECPublicKeyParameters) pubKey;
-            ECDomainParameters parameters = pub.Parameters;
-            if (!parameters.Equals(privKey.Parameters))
+            ECPublicKeyParameters pub = (ECPublicKeyParameters)pubKey;
+            ECDomainParameters dp = privKey.Parameters;
+            if (!dp.Equals(pub.Parameters))
                 throw new InvalidOperationException("ECDHC public key has wrong domain parameters");
 
-            BigInteger hd = parameters.H.Multiply(privKey.D).Mod(parameters.N);
+            BigInteger hd = dp.H.Multiply(privKey.D).Mod(dp.N);
 
-            ECPoint P = pub.Q.Multiply(hd).Normalize();
+            // Always perform calculations on the exact curve specified by our private key's parameters
+            ECPoint pubPoint = ECAlgorithms.CleanPoint(dp.Curve, pub.Q);
+            if (pubPoint.IsInfinity)
+                throw new InvalidOperationException("Infinity is not a valid public key for ECDHC");
 
+            ECPoint P = pubPoint.Multiply(hd).Normalize();
             if (P.IsInfinity)
                 throw new InvalidOperationException("Infinity is not a valid agreement value for ECDHC");
 
diff --git a/crypto/src/crypto/agreement/ECMqvBasicAgreement.cs b/crypto/src/crypto/agreement/ECMqvBasicAgreement.cs
index 8d5cebb13..b71f5a7d2 100644
--- a/crypto/src/crypto/agreement/ECMqvBasicAgreement.cs
+++ b/crypto/src/crypto/agreement/ECMqvBasicAgreement.cs
@@ -64,16 +64,9 @@ namespace Org.BouncyCastle.Crypto.Agreement
 
             ECCurve curve = parameters.Curve;
 
-            ECPoint[] points = new ECPoint[]{
-                // The Q2U public key is optional - but will be calculated for us if it wasn't present
-                ECAlgorithms.ImportPoint(curve, Q2U.Q),
-                ECAlgorithms.ImportPoint(curve, Q1V.Q),
-                ECAlgorithms.ImportPoint(curve, Q2V.Q)
-            };
-
-            curve.NormalizeAll(points);
-
-            ECPoint q2u = points[0], q1v = points[1], q2v = points[2];
+            ECPoint q2u = ECAlgorithms.CleanPoint(curve, Q2U.Q);
+            ECPoint q1v = ECAlgorithms.CleanPoint(curve, Q1V.Q);
+            ECPoint q2v = ECAlgorithms.CleanPoint(curve, Q2V.Q);
 
             BigInteger x = q2u.AffineXCoord.ToBigInteger();
             BigInteger xBar = x.Mod(powE);
diff --git a/crypto/src/crypto/agreement/SM2KeyExchange.cs b/crypto/src/crypto/agreement/SM2KeyExchange.cs
index 1cfcd6a3a..986d98421 100644
--- a/crypto/src/crypto/agreement/SM2KeyExchange.cs
+++ b/crypto/src/crypto/agreement/SM2KeyExchange.cs
@@ -144,8 +144,10 @@ namespace Org.BouncyCastle.Crypto.Agreement
 
         protected virtual ECPoint CalculateU(SM2KeyExchangePublicParameters otherPub)
         {
-            ECPoint p1 = otherPub.StaticPublicKey.Q;
-            ECPoint p2 = otherPub.EphemeralPublicKey.Q;
+            ECDomainParameters dp = mStaticKey.Parameters;
+
+            ECPoint p1 = ECAlgorithms.CleanPoint(dp.Curve, otherPub.StaticPublicKey.Q);
+            ECPoint p2 = ECAlgorithms.CleanPoint(dp.Curve, otherPub.EphemeralPublicKey.Q);
 
             BigInteger x1 = Reduce(mEphemeralPubPoint.AffineXCoord.ToBigInteger());
             BigInteger x2 = Reduce(p2.AffineXCoord.ToBigInteger());
diff --git a/crypto/src/crypto/engines/Cast5Engine.cs b/crypto/src/crypto/engines/Cast5Engine.cs
index 53836db02..398f6d43a 100644
--- a/crypto/src/crypto/engines/Cast5Engine.cs
+++ b/crypto/src/crypto/engines/Cast5Engine.cs
@@ -20,7 +20,7 @@ namespace Org.BouncyCastle.Crypto.Engines
     public class Cast5Engine
 		: IBlockCipher
     {
-		internal static readonly uint[] S1 =
+		private static readonly uint[] S1 =
 		{
 			0x30fb40d4, 0x9fa0ff0b, 0x6beccd2f, 0x3f258c7a, 0x1e213f2f, 0x9c004dd3, 0x6003e540, 0xcf9fc949,
 			0xbfd4af27, 0x88bbbdb5, 0xe2034090, 0x98d09675, 0x6e63a0e0, 0x15c361d2, 0xc2e7661d, 0x22d4ff8e,
diff --git a/crypto/src/crypto/engines/IdeaEngine.cs b/crypto/src/crypto/engines/IdeaEngine.cs
index 18a151c93..6c0379174 100644
--- a/crypto/src/crypto/engines/IdeaEngine.cs
+++ b/crypto/src/crypto/engines/IdeaEngine.cs
@@ -9,24 +9,14 @@ namespace Org.BouncyCastle.Crypto.Engines
     * A class that provides a basic International Data Encryption Algorithm (IDEA) engine.
     * <p>
     * This implementation is based on the "HOWTO: INTERNATIONAL DATA ENCRYPTION ALGORITHM"
-    * implementation summary by Fauzan Mirza (F.U.Mirza@sheffield.ac.uk). (baring 1 typo at the
-    * end of the mulinv function!).
+    * implementation summary by Fauzan Mirza (F.U.Mirza@sheffield.ac.uk). (barring 1 typo at the
+    * end of the MulInv function!).
     * </p>
     * <p>
     * It can be found at ftp://ftp.funet.fi/pub/crypt/cryptography/symmetric/idea/
     * </p>
     * <p>
-    * Note 1: This algorithm is patented in the USA, Japan, and Europe including
-    * at least Austria, France, Germany, Italy, Netherlands, Spain, Sweden, Switzerland
-    * and the United Kingdom. Non-commercial use is free, however any commercial
-    * products are liable for royalties. Please see
-    * <a href="http://www.mediacrypt.com">www.mediacrypt.com</a> for
-    * further details. This announcement has been included at the request of
-    * the patent holders.
-    * </p>
-    * <p>
-    * Note 2: Due to the requests concerning the above, this algorithm is now only
-    * included in the extended assembly. It is not included in the default distributions.
+    * Note: This algorithm was patented in the USA, Japan and Europe. These patents expired in 2011/2012.
     * </p>
     */
     public class IdeaEngine
diff --git a/crypto/src/crypto/parameters/ECDomainParameters.cs b/crypto/src/crypto/parameters/ECDomainParameters.cs
index 732fbdfa4..e377f7760 100644
--- a/crypto/src/crypto/parameters/ECDomainParameters.cs
+++ b/crypto/src/crypto/parameters/ECDomainParameters.cs
@@ -13,12 +13,13 @@ namespace Org.BouncyCastle.Crypto.Parameters
         internal ECPoint     g;
         internal BigInteger  n;
         internal BigInteger  h;
+        internal BigInteger  hInv;
 
         public ECDomainParameters(
             ECCurve     curve,
             ECPoint     g,
             BigInteger  n)
-            : this(curve, g, n, BigInteger.One)
+            : this(curve, g, n, BigInteger.One, null)
         {
         }
 
@@ -44,11 +45,10 @@ namespace Org.BouncyCastle.Crypto.Parameters
                 throw new ArgumentNullException("g");
             if (n == null)
                 throw new ArgumentNullException("n");
-            if (h == null)
-                throw new ArgumentNullException("h");
+            // we can't check for h == null here as h is optional in X9.62 as it is not required for ECDSA
 
             this.curve = curve;
-            this.g = g.Normalize();
+            this.g = Validate(curve, g);
             this.n = n;
             this.h = h;
             this.seed = Arrays.Clone(seed);
@@ -74,6 +74,21 @@ namespace Org.BouncyCastle.Crypto.Parameters
             get { return h; }
         }
 
+        public BigInteger HInv
+        {
+            get
+            {
+                lock (this)
+                {
+                    if (hInv == null)
+                    {
+                        hInv = h.ModInverse(n);
+                    }
+                    return hInv;
+                }
+            }
+        }
+
         public byte[] GetSeed()
         {
             return Arrays.Clone(seed);
@@ -99,7 +114,7 @@ namespace Org.BouncyCastle.Crypto.Parameters
             return curve.Equals(other.curve)
                 &&	g.Equals(other.g)
                 &&	n.Equals(other.n)
-                &&	h.Equals(other.h);
+                &&  h.Equals(other.h);
         }
 
         public override int GetHashCode()
@@ -113,5 +128,21 @@ namespace Org.BouncyCastle.Crypto.Parameters
             hc ^= h.GetHashCode();
             return hc;
         }
+
+        internal static ECPoint Validate(ECCurve c, ECPoint q)
+        {
+            if (q == null)
+                throw new ArgumentException("Point has null value", "q");
+
+            q = ECAlgorithms.ImportPoint(c, q).Normalize();
+
+            if (q.IsInfinity)
+                throw new ArgumentException("Point at infinity", "q");
+
+            if (!q.IsValid())
+                throw new ArgumentException("Point not on curve", "q");
+
+            return q;
+        }
     }
 }
diff --git a/crypto/src/crypto/parameters/ECPublicKeyParameters.cs b/crypto/src/crypto/parameters/ECPublicKeyParameters.cs
index 474e5d82c..69916e525 100644
--- a/crypto/src/crypto/parameters/ECPublicKeyParameters.cs
+++ b/crypto/src/crypto/parameters/ECPublicKeyParameters.cs
@@ -9,21 +9,6 @@ namespace Org.BouncyCastle.Crypto.Parameters
     public class ECPublicKeyParameters
         : ECKeyParameters
     {
-        private static ECPoint Validate(ECPoint q)
-        {
-            if (q == null)
-                throw new ArgumentNullException("q");
-            if (q.IsInfinity)
-                throw new ArgumentException("point at infinity", "q");
-
-            q = q.Normalize();
-
-            if (!q.IsValid())
-                throw new ArgumentException("point not on curve", "q");
-
-            return q;
-        }
-
         private readonly ECPoint q;
 
         public ECPublicKeyParameters(
@@ -42,7 +27,7 @@ namespace Org.BouncyCastle.Crypto.Parameters
             if (q == null)
                 throw new ArgumentNullException("q");
 
-            this.q = Validate(q);
+            this.q = ECDomainParameters.Validate(Parameters.Curve, q);
         }
 
         public ECPublicKeyParameters(
@@ -54,7 +39,7 @@ namespace Org.BouncyCastle.Crypto.Parameters
             if (q == null)
                 throw new ArgumentNullException("q");
 
-            this.q = Validate(q);
+            this.q = ECDomainParameters.Validate(Parameters.Curve, q);
         }
 
         public ECPublicKeyParameters(
@@ -66,7 +51,7 @@ namespace Org.BouncyCastle.Crypto.Parameters
             if (q == null)
                 throw new ArgumentNullException("q");
 
-            this.q = Validate(q);
+            this.q = ECDomainParameters.Validate(Parameters.Curve, q);
         }
 
         public ECPoint Q
diff --git a/crypto/src/math/ec/ECAlgorithms.cs b/crypto/src/math/ec/ECAlgorithms.cs
index 5d60de40f..b05c0201a 100644
--- a/crypto/src/math/ec/ECAlgorithms.cs
+++ b/crypto/src/math/ec/ECAlgorithms.cs
@@ -58,10 +58,10 @@ namespace Org.BouncyCastle.Math.EC
             GlvEndomorphism glvEndomorphism = c.GetEndomorphism() as GlvEndomorphism;
             if (glvEndomorphism != null)
             {
-                return ValidatePoint(ImplSumOfMultipliesGlv(imported, ks, glvEndomorphism));
+                return ImplCheckResult(ImplSumOfMultipliesGlv(imported, ks, glvEndomorphism));
             }
 
-            return ValidatePoint(ImplSumOfMultiplies(imported, ks));
+            return ImplCheckResult(ImplSumOfMultiplies(imported, ks));
         }
 
         public static ECPoint SumOfTwoMultiplies(ECPoint P, BigInteger a, ECPoint Q, BigInteger b)
@@ -74,18 +74,18 @@ namespace Org.BouncyCastle.Math.EC
                 AbstractF2mCurve f2mCurve = cp as AbstractF2mCurve;
                 if (f2mCurve != null && f2mCurve.IsKoblitz)
                 {
-                    return ValidatePoint(P.Multiply(a).Add(Q.Multiply(b)));
+                    return ImplCheckResult(P.Multiply(a).Add(Q.Multiply(b)));
                 }
             }
 
             GlvEndomorphism glvEndomorphism = cp.GetEndomorphism() as GlvEndomorphism;
             if (glvEndomorphism != null)
             {
-                return ValidatePoint(
+                return ImplCheckResult(
                     ImplSumOfMultipliesGlv(new ECPoint[] { P, Q }, new BigInteger[] { a, b }, glvEndomorphism));
             }
 
-            return ValidatePoint(ImplShamirsTrickWNaf(P, a, Q, b));
+            return ImplCheckResult(ImplShamirsTrickWNaf(P, a, Q, b));
         }
 
         /*
@@ -111,7 +111,7 @@ namespace Org.BouncyCastle.Math.EC
             ECCurve cp = P.Curve;
             Q = ImportPoint(cp, Q);
 
-            return ValidatePoint(ImplShamirsTrickJsf(P, k, Q, l));
+            return ImplCheckResult(ImplShamirsTrickJsf(P, k, Q, l));
         }
 
         public static ECPoint ImportPoint(ECCurve c, ECPoint p)
@@ -202,7 +202,24 @@ namespace Org.BouncyCastle.Math.EC
         public static ECPoint ValidatePoint(ECPoint p)
         {
             if (!p.IsValid())
-                throw new ArgumentException("Invalid point", "p");
+                throw new InvalidOperationException("Invalid point");
+
+            return p;
+        }
+
+        public static ECPoint CleanPoint(ECCurve c, ECPoint p)
+        {
+            ECCurve cp = p.Curve;
+            if (!c.Equals(cp))
+                throw new ArgumentException("Point must be on the same curve", "p");
+
+            return c.DecodePoint(p.GetEncoded(false));
+        }
+
+        internal static ECPoint ImplCheckResult(ECPoint p)
+        {
+            if (!p.IsValidPartial())
+                throw new InvalidOperationException("Invalid result");
 
             return p;
         }
diff --git a/crypto/src/math/ec/ECCurve.cs b/crypto/src/math/ec/ECCurve.cs
index 6a9342722..993b69149 100644
--- a/crypto/src/math/ec/ECCurve.cs
+++ b/crypto/src/math/ec/ECCurve.cs
@@ -161,15 +161,24 @@ namespace Org.BouncyCastle.Math.EC
         public virtual PreCompInfo GetPreCompInfo(ECPoint point, string name)
         {
             CheckPoint(point);
+
+            IDictionary table;
             lock (point)
             {
-                IDictionary table = point.m_preCompTable;
-                return table == null ? null : (PreCompInfo)table[name];
+                table = point.m_preCompTable;
+            }
+
+            if (null == table)
+                return null;
+
+            lock (table)
+            {
+                return (PreCompInfo)table[name];
             }
         }
 
         /**
-         * Adds <code>PreCompInfo</code> for a point on this curve, under a given name. Used by
+         * Compute a <code>PreCompInfo</code> for a point on this curve, under a given name. Used by
          * <code>ECMultiplier</code>s to save the precomputation for this <code>ECPoint</code> for use
          * by subsequent multiplication.
          * 
@@ -177,20 +186,34 @@ namespace Org.BouncyCastle.Math.EC
          *            The <code>ECPoint</code> to store precomputations for.
          * @param name
          *            A <code>String</code> used to index precomputations of different types.
-         * @param preCompInfo
-         *            The values precomputed by the <code>ECMultiplier</code>.
+         * @param callback
+         *            Called to calculate the <code>PreCompInfo</code>.
          */
-        public virtual void SetPreCompInfo(ECPoint point, string name, PreCompInfo preCompInfo)
+        public virtual PreCompInfo Precompute(ECPoint point, string name, IPreCompCallback callback)
         {
             CheckPoint(point);
+
+            IDictionary table;
             lock (point)
             {
-                IDictionary table = point.m_preCompTable;
+                table = point.m_preCompTable;
                 if (null == table)
                 {
                     point.m_preCompTable = table = Platform.CreateHashtable(4);
                 }
-                table[name] = preCompInfo;
+            }
+
+            lock (table)
+            {
+                PreCompInfo existing = (PreCompInfo)table[name];
+                PreCompInfo result = callback.Precompute(existing);
+
+                if (result != existing)
+                {
+                    table[name] = result;
+                }
+
+                return result;
             }
         }
 
@@ -208,7 +231,7 @@ namespace Org.BouncyCastle.Math.EC
             // TODO Default behaviour could be improved if the two curves have the same coordinate system by copying any Z coordinates.
             p = p.Normalize();
 
-            return ValidatePoint(p.XCoord.ToBigInteger(), p.YCoord.ToBigInteger(), p.IsCompressed);
+            return CreatePoint(p.XCoord.ToBigInteger(), p.YCoord.ToBigInteger(), p.IsCompressed);
         }
 
         /**
@@ -453,7 +476,7 @@ namespace Org.BouncyCastle.Math.EC
                     BigInteger X = new BigInteger(1, encoded, 1, expectedLength);
 
                     p = DecompressPoint(yTilde, X);
-                    if (!p.SatisfiesCofactor())
+                    if (!p.ImplIsValid(true, true))
                         throw new ArgumentException("Invalid point");
 
                     break;
@@ -588,6 +611,7 @@ namespace Org.BouncyCastle.Math.EC
         protected readonly BigInteger m_q, m_r;
         protected readonly FpPoint m_infinity;
 
+        [Obsolete("Use constructor taking order/cofactor")]
         public FpCurve(BigInteger q, BigInteger a, BigInteger b)
             : this(q, a, b, null, null)
         {
@@ -598,7 +622,7 @@ namespace Org.BouncyCastle.Math.EC
         {
             this.m_q = q;
             this.m_r = FpFieldElement.CalculateResidue(q);
-            this.m_infinity = new FpPoint(this, null, null);
+            this.m_infinity = new FpPoint(this, null, null, false);
 
             this.m_a = FromBigInteger(a);
             this.m_b = FromBigInteger(b);
@@ -607,6 +631,7 @@ namespace Org.BouncyCastle.Math.EC
             this.m_coord = FP_DEFAULT_COORDS;
         }
 
+        [Obsolete("Use constructor taking order/cofactor")]
         protected FpCurve(BigInteger q, BigInteger r, ECFieldElement a, ECFieldElement b)
             : this(q, r, a, b, null, null)
         {
@@ -617,7 +642,7 @@ namespace Org.BouncyCastle.Math.EC
         {
             this.m_q = q;
             this.m_r = r;
-            this.m_infinity = new FpPoint(this, null, null);
+            this.m_infinity = new FpPoint(this, null, null, false);
 
             this.m_a = a;
             this.m_b = b;
@@ -794,7 +819,7 @@ namespace Org.BouncyCastle.Math.EC
             else
             {
                 ECFieldElement beta = xp.Square().Invert().Multiply(B).Add(A).Add(xp);
-                ECFieldElement z = SolveQuadradicEquation(beta);
+                ECFieldElement z = SolveQuadraticEquation(beta);
 
                 if (z != null)
                 {
@@ -831,11 +856,11 @@ namespace Org.BouncyCastle.Math.EC
          * D.1.6) The other solution is <code>z + 1</code>.
          *
          * @param beta
-         *            The value to solve the qradratic equation for.
+         *            The value to solve the quadratic equation for.
          * @return the solution for <code>z<sup>2</sup> + z = beta</code> or
          *         <code>null</code> if no solution exists.
          */
-        private ECFieldElement SolveQuadradicEquation(ECFieldElement beta)
+        internal ECFieldElement SolveQuadraticEquation(ECFieldElement beta)
         {
             if (beta.IsZero)
                 return beta;
@@ -957,6 +982,7 @@ namespace Org.BouncyCastle.Math.EC
          * for non-supersingular elliptic curves over
          * <code>F<sub>2<sup>m</sup></sub></code>.
          */
+        [Obsolete("Use constructor taking order/cofactor")]
         public F2mCurve(
             int			m,
             int			k,
@@ -1014,6 +1040,7 @@ namespace Org.BouncyCastle.Math.EC
          * for non-supersingular elliptic curves over
          * <code>F<sub>2<sup>m</sup></sub></code>.
          */
+        [Obsolete("Use constructor taking order/cofactor")]
         public F2mCurve(
             int			m,
             int			k1,
@@ -1065,7 +1092,7 @@ namespace Org.BouncyCastle.Math.EC
             this.k3 = k3;
             this.m_order = order;
             this.m_cofactor = cofactor;
-            this.m_infinity = new F2mPoint(this, null, null);
+            this.m_infinity = new F2mPoint(this, null, null, false);
 
             if (k1 == 0)
                 throw new ArgumentException("k1 must be > 0");
@@ -1099,7 +1126,7 @@ namespace Org.BouncyCastle.Math.EC
             this.m_order = order;
             this.m_cofactor = cofactor;
 
-            this.m_infinity = new F2mPoint(this, null, null);
+            this.m_infinity = new F2mPoint(this, null, null, false);
             this.m_a = a;
             this.m_b = b;
             this.m_coord = F2M_DEFAULT_COORDS;
@@ -1188,18 +1215,6 @@ namespace Org.BouncyCastle.Math.EC
             get { return k3; }
         }
 
-        [Obsolete("Use 'Order' property instead")]
-        public BigInteger N
-        {
-            get { return m_order; }
-        }
-
-        [Obsolete("Use 'Cofactor' property instead")]
-        public BigInteger H
-        {
-            get { return m_cofactor; }
-        }
-
         public override ECLookupTable CreateCacheSafeLookupTable(ECPoint[] points, int off, int len)
         {
             int FE_LONGS = (m + 63) / 64;
diff --git a/crypto/src/math/ec/ECFieldElement.cs b/crypto/src/math/ec/ECFieldElement.cs
index 3676c81b1..350e8c6d4 100644
--- a/crypto/src/math/ec/ECFieldElement.cs
+++ b/crypto/src/math/ec/ECFieldElement.cs
@@ -101,9 +101,14 @@ namespace Org.BouncyCastle.Math.EC
         }
     }
 
-    public class FpFieldElement
+    public abstract class AbstractFpFieldElement
         : ECFieldElement
     {
+    }
+
+    public class FpFieldElement
+        : AbstractFpFieldElement
+    {
         private readonly BigInteger q, r, x;
 
         internal static BigInteger CalculateResidue(BigInteger p)
@@ -536,6 +541,45 @@ namespace Org.BouncyCastle.Math.EC
         }
     }
 
+    public abstract class AbstractF2mFieldElement
+        :   ECFieldElement
+    {
+        public virtual ECFieldElement HalfTrace()
+        {
+            int m = FieldSize;
+            if ((m & 1) == 0)
+                throw new InvalidOperationException("Half-trace only defined for odd m");
+
+            ECFieldElement fe = this;
+            ECFieldElement ht = fe;
+            for (int i = 2; i < m; i += 2)
+            {
+                fe = fe.SquarePow(2);
+                ht = ht.Add(fe);
+            }
+
+            return ht;
+        }
+
+        public virtual int Trace()
+        {
+            int m = FieldSize;
+            ECFieldElement fe = this;
+            ECFieldElement tr = fe;
+            for (int i = 1; i < m; ++i)
+            {
+                fe = fe.Square();
+                tr = tr.Add(fe);
+            }
+            if (tr.IsZero)
+                return 0;
+            if (tr.IsOne)
+                return 1;
+
+            throw new InvalidOperationException("Internal error in trace calculation");
+        }
+    }
+
     /**
      * Class representing the Elements of the finite field
      * <code>F<sub>2<sup>m</sup></sub></code> in polynomial basis (PB)
@@ -544,7 +588,7 @@ namespace Org.BouncyCastle.Math.EC
      * representation is not supported.
      */
     public class F2mFieldElement
-        : ECFieldElement
+        :   AbstractF2mFieldElement
     {
         /**
          * Indicates gaussian normal basis representation (GNB). Number chosen
@@ -582,20 +626,21 @@ namespace Org.BouncyCastle.Math.EC
         internal LongArray x;
 
         /**
-            * Constructor for Ppb.
-            * @param m  The exponent <code>m</code> of
-            * <code>F<sub>2<sup>m</sup></sub></code>.
-            * @param k1 The integer <code>k1</code> where <code>x<sup>m</sup> +
-            * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
-            * represents the reduction polynomial <code>f(z)</code>.
-            * @param k2 The integer <code>k2</code> where <code>x<sup>m</sup> +
-            * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
-            * represents the reduction polynomial <code>f(z)</code>.
-            * @param k3 The integer <code>k3</code> where <code>x<sup>m</sup> +
-            * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
-            * represents the reduction polynomial <code>f(z)</code>.
-            * @param x The BigInteger representing the value of the field element.
-            */
+         * Constructor for Ppb.
+         * @param m  The exponent <code>m</code> of
+         * <code>F<sub>2<sup>m</sup></sub></code>.
+         * @param k1 The integer <code>k1</code> where <code>x<sup>m</sup> +
+         * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
+         * represents the reduction polynomial <code>f(z)</code>.
+         * @param k2 The integer <code>k2</code> where <code>x<sup>m</sup> +
+         * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
+         * represents the reduction polynomial <code>f(z)</code>.
+         * @param k3 The integer <code>k3</code> where <code>x<sup>m</sup> +
+         * x<sup>k3</sup> + x<sup>k2</sup> + x<sup>k1</sup> + 1</code>
+         * represents the reduction polynomial <code>f(z)</code>.
+         * @param x The BigInteger representing the value of the field element.
+         */
+        [Obsolete("Use ECCurve.FromBigInteger to construct field elements")]
         public F2mFieldElement(
             int			m,
             int			k1,
@@ -627,14 +672,15 @@ namespace Org.BouncyCastle.Math.EC
         }
 
         /**
-            * Constructor for Tpb.
-            * @param m  The exponent <code>m</code> of
-            * <code>F<sub>2<sup>m</sup></sub></code>.
-            * @param k The integer <code>k</code> where <code>x<sup>m</sup> +
-            * x<sup>k</sup> + 1</code> represents the reduction
-            * polynomial <code>f(z)</code>.
-            * @param x The BigInteger representing the value of the field element.
-            */
+         * Constructor for Tpb.
+         * @param m  The exponent <code>m</code> of
+         * <code>F<sub>2<sup>m</sup></sub></code>.
+         * @param k The integer <code>k</code> where <code>x<sup>m</sup> +
+         * x<sup>k</sup> + 1</code> represents the reduction
+         * polynomial <code>f(z)</code>.
+         * @param x The BigInteger representing the value of the field element.
+         */
+        [Obsolete("Use ECCurve.FromBigInteger to construct field elements")]
         public F2mFieldElement(
             int			m,
             int			k,
diff --git a/crypto/src/math/ec/ECPoint.cs b/crypto/src/math/ec/ECPoint.cs
index a5ba515c5..2acc9f5c0 100644
--- a/crypto/src/math/ec/ECPoint.cs
+++ b/crypto/src/math/ec/ECPoint.cs
@@ -67,13 +67,19 @@ namespace Org.BouncyCastle.Math.EC
             this.m_withCompression = withCompression;
         }
 
-        protected internal bool SatisfiesCofactor()
+        protected abstract bool SatisfiesCurveEquation();
+
+        protected virtual bool SatisfiesOrder()
         {
-            BigInteger h = Curve.Cofactor;
-            return h == null || h.Equals(BigInteger.One) || !ECAlgorithms.ReferenceMultiply(this, h).IsInfinity;
-        }
+            if (BigInteger.One.Equals(Curve.Cofactor))
+                return true;
 
-        protected abstract bool SatisfiesCurveEquation();
+            BigInteger n = Curve.Order;
+
+            // TODO Require order to be available for all curves
+
+            return n == null || ECAlgorithms.ReferenceMultiply(this, n).IsInfinity;
+        }
 
         public ECPoint GetDetachedPoint()
         {
@@ -97,30 +103,6 @@ namespace Org.BouncyCastle.Math.EC
         }
 
         /**
-         * Normalizes this point, and then returns the affine x-coordinate.
-         * 
-         * Note: normalization can be expensive, this method is deprecated in favour
-         * of caller-controlled normalization.
-         */
-        [Obsolete("Use AffineXCoord, or Normalize() and XCoord, instead")]
-        public virtual ECFieldElement X
-        {
-            get { return Normalize().XCoord; }
-        }
-
-        /**
-         * Normalizes this point, and then returns the affine y-coordinate.
-         * 
-         * Note: normalization can be expensive, this method is deprecated in favour
-         * of caller-controlled normalization.
-         */
-        [Obsolete("Use AffineYCoord, or Normalize() and YCoord, instead")]
-        public virtual ECFieldElement Y
-        {
-            get { return Normalize().YCoord; }
-        }
-
-        /**
          * Returns the affine x-coordinate after checking that this point is normalized.
          * 
          * @return The affine x-coordinate of this point
@@ -299,22 +281,22 @@ namespace Org.BouncyCastle.Math.EC
 
         public bool IsValid()
         {
-            if (IsInfinity)
-                return true;
-
-            // TODO Sanity-check the field elements
+            return ImplIsValid(false, true);
+        }
 
-            ECCurve curve = Curve;
-            if (curve != null)
-            {
-                if (!SatisfiesCurveEquation())
-                    return false;
+        internal bool IsValidPartial()
+        {
+            return ImplIsValid(false, false);
+        }
 
-                if (!SatisfiesCofactor())
-                    return false;
-            }
+        internal bool ImplIsValid(bool decompressed, bool checkOrder)
+        {
+            if (IsInfinity)
+                return true;
 
-            return true;
+            ValidityCallback callback = new ValidityCallback(this, decompressed, checkOrder);
+            ValidityPreCompInfo validity = (ValidityPreCompInfo)Curve.Precompute(this, ValidityPreCompInfo.PRECOMP_NAME, callback);
+            return !validity.HasFailed();
         }
 
         public virtual ECPoint ScaleX(ECFieldElement scale)
@@ -462,6 +444,52 @@ namespace Org.BouncyCastle.Math.EC
         {
             return TwicePlus(this);
         }
+
+        private class ValidityCallback
+            : IPreCompCallback
+        {
+            private readonly ECPoint m_outer;
+            private readonly bool m_decompressed, m_checkOrder;
+
+            internal ValidityCallback(ECPoint outer, bool decompressed, bool checkOrder)
+            {
+                this.m_outer = outer;
+                this.m_decompressed = decompressed;
+                this.m_checkOrder = checkOrder;
+            }
+
+            public PreCompInfo Precompute(PreCompInfo existing)
+            {
+                ValidityPreCompInfo info = existing as ValidityPreCompInfo;
+                if (info == null)
+                {
+                    info = new ValidityPreCompInfo();
+                }
+
+                if (info.HasFailed())
+                    return info;
+
+                if (!info.HasCurveEquationPassed())
+                {
+                    if (!m_decompressed && !m_outer.SatisfiesCurveEquation())
+                    {
+                        info.ReportFailed();
+                        return info;
+                    }
+                    info.ReportCurveEquationPassed();
+                }
+                if (m_checkOrder && !info.HasOrderPassed())
+                {
+                    if (!m_outer.SatisfiesOrder())
+                    {
+                        info.ReportFailed();
+                        return info;
+                    }
+                    info.ReportOrderPassed();
+                }
+                return info;
+            }
+        }
     }
 
     public abstract class ECPointBase
@@ -608,6 +636,7 @@ namespace Org.BouncyCastle.Math.EC
          * @param x affine x co-ordinate
          * @param y affine y co-ordinate
          */
+        [Obsolete("Use ECCurve.CreatePoint to construct points")]
         public FpPoint(ECCurve curve, ECFieldElement x, ECFieldElement y)
             : this(curve, x, y, false)
         {
@@ -621,6 +650,7 @@ namespace Org.BouncyCastle.Math.EC
          * @param y affine y co-ordinate
          * @param withCompression if true encode with point compression
          */
+        [Obsolete("Per-point compression property will be removed, see GetEncoded(bool)")]
         public FpPoint(ECCurve curve, ECFieldElement x, ECFieldElement y, bool withCompression)
             : base(curve, x, y, withCompression)
         {
@@ -635,7 +665,7 @@ namespace Org.BouncyCastle.Math.EC
 
         protected override ECPoint Detach()
         {
-            return new FpPoint(null, AffineXCoord, AffineYCoord);
+            return new FpPoint(null, AffineXCoord, AffineYCoord, false);
         }
 
         public override ECFieldElement GetZCoord(int index)
@@ -1384,6 +1414,46 @@ namespace Org.BouncyCastle.Math.EC
             return lhs.Equals(rhs);
         }
 
+        protected override bool SatisfiesOrder()
+        {
+            ECCurve curve = Curve;
+            BigInteger cofactor = curve.Cofactor;
+            if (BigInteger.Two.Equals(cofactor))
+            {
+                /*
+                 *  Check that the trace of (X + A) is 0, then there exists a solution to L^2 + L = X + A,
+                 *  and so a halving is possible, so this point is the double of another.  
+                 */
+                ECPoint N = this.Normalize();
+                ECFieldElement X = N.AffineXCoord;
+                ECFieldElement rhs = X.Add(curve.A);
+                return ((AbstractF2mFieldElement)rhs).Trace() == 0;
+            }
+            if (BigInteger.ValueOf(4).Equals(cofactor))
+            {
+                /*
+                 * Solve L^2 + L = X + A to find the half of this point, if it exists (fail if not).
+                 * Generate both possibilities for the square of the half-point's x-coordinate (w),
+                 * and check if Tr(w + A) == 0 for at least one; then a second halving is possible
+                 * (see comments for cofactor 2 above), so this point is four times another.
+                 * 
+                 * Note: Tr(x^2) == Tr(x). 
+                 */
+                ECPoint N = this.Normalize();
+                ECFieldElement X = N.AffineXCoord;
+                ECFieldElement lambda = ((AbstractF2mCurve)curve).SolveQuadraticEquation(X.Add(curve.A));
+                if (lambda == null)
+                    return false;
+
+                ECFieldElement w = X.Multiply(lambda).Add(N.AffineYCoord);
+                ECFieldElement t = w.Add(curve.A);
+                return ((AbstractF2mFieldElement)t).Trace() == 0
+                    || ((AbstractF2mFieldElement)(t.Add(X))).Trace() == 0;
+            }
+
+            return base.SatisfiesOrder();
+        }
+
         public override ECPoint ScaleX(ECFieldElement scale)
         {
             if (this.IsInfinity)
@@ -1529,6 +1599,7 @@ namespace Org.BouncyCastle.Math.EC
          * @param x x point
          * @param y y point
          */
+        [Obsolete("Use ECCurve.CreatePoint to construct points")]
         public F2mPoint(
             ECCurve			curve,
             ECFieldElement	x,
@@ -1543,6 +1614,7 @@ namespace Org.BouncyCastle.Math.EC
          * @param y y point
          * @param withCompression true if encode with point compression.
          */
+        [Obsolete("Per-point compression property will be removed, see GetEncoded(bool)")]
         public F2mPoint(
             ECCurve			curve,
             ECFieldElement	x,
@@ -1573,19 +1645,9 @@ namespace Org.BouncyCastle.Math.EC
         {
         }
 
-        /**
-         * Constructor for point at infinity
-         */
-        [Obsolete("Use ECCurve.Infinity property")]
-        public F2mPoint(
-            ECCurve curve)
-            : this(curve, null, null)
-        {
-        }
-
         protected override ECPoint Detach()
         {
-            return new F2mPoint(null, AffineXCoord, AffineYCoord);
+            return new F2mPoint(null, AffineXCoord, AffineYCoord, false);
         }
 
         public override ECFieldElement YCoord
diff --git a/crypto/src/math/ec/custom/djb/Curve25519FieldElement.cs b/crypto/src/math/ec/custom/djb/Curve25519FieldElement.cs
index 732e9e468..37256a550 100644
--- a/crypto/src/math/ec/custom/djb/Curve25519FieldElement.cs
+++ b/crypto/src/math/ec/custom/djb/Curve25519FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Djb
 {
     internal class Curve25519FieldElement
-        :   ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = Curve25519.q;
 
diff --git a/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs b/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs
index 4f6428f9e..087a040f2 100644
--- a/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs
+++ b/crypto/src/math/ec/custom/gm/SM2P256V1FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.GM
 {
     internal class SM2P256V1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SM2P256V1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP128R1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP128R1FieldElement.cs
index fa7951d5d..5912a87e8 100644
--- a/crypto/src/math/ec/custom/sec/SecP128R1FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP128R1FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP128R1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP128R1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP160R1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP160R1FieldElement.cs
index d1fc75644..3ab11bdae 100644
--- a/crypto/src/math/ec/custom/sec/SecP160R1FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP160R1FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP160R1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP160R1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP160R2FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP160R2FieldElement.cs
index bdb5245b2..9d8131857 100644
--- a/crypto/src/math/ec/custom/sec/SecP160R2FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP160R2FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP160R2FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP160R2Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP192K1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP192K1FieldElement.cs
index dce377035..54b72573c 100644
--- a/crypto/src/math/ec/custom/sec/SecP192K1FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP192K1FieldElement.cs
@@ -7,7 +7,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP192K1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP192K1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP192R1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP192R1FieldElement.cs
index 45bcb00f0..f3e12b542 100644
--- a/crypto/src/math/ec/custom/sec/SecP192R1FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP192R1FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP192R1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP192R1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP224K1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP224K1FieldElement.cs
index fec07436a..ef53a88d6 100644
--- a/crypto/src/math/ec/custom/sec/SecP224K1FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP224K1FieldElement.cs
@@ -7,7 +7,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP224K1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP224K1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP224R1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP224R1FieldElement.cs
index 2b9a06564..5780b7481 100644
--- a/crypto/src/math/ec/custom/sec/SecP224R1FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP224R1FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP224R1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP224R1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP256K1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP256K1FieldElement.cs
index 473113d0f..9a604bdb7 100644
--- a/crypto/src/math/ec/custom/sec/SecP256K1FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP256K1FieldElement.cs
@@ -7,7 +7,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP256K1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP256K1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP256R1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP256R1FieldElement.cs
index d7838aead..808e99ea6 100644
--- a/crypto/src/math/ec/custom/sec/SecP256R1FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP256R1FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP256R1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP256R1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP384R1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP384R1FieldElement.cs
index 18d48a57d..7eedccae6 100644
--- a/crypto/src/math/ec/custom/sec/SecP384R1FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP384R1FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP384R1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP384R1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecP521R1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP521R1FieldElement.cs
index 6f02a7eb5..96658a8e5 100644
--- a/crypto/src/math/ec/custom/sec/SecP521R1FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecP521R1FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecP521R1FieldElement
-        : ECFieldElement
+        : AbstractFpFieldElement
     {
         public static readonly BigInteger Q = SecP521R1Curve.q;
 
diff --git a/crypto/src/math/ec/custom/sec/SecT113FieldElement.cs b/crypto/src/math/ec/custom/sec/SecT113FieldElement.cs
index 9ba25d987..bb87b00fc 100644
--- a/crypto/src/math/ec/custom/sec/SecT113FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecT113FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecT113FieldElement
-        : ECFieldElement
+        : AbstractF2mFieldElement
     {
         protected internal readonly ulong[] x;
 
@@ -150,6 +150,11 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
             return new SecT113FieldElement(z);
         }
 
+        public override int Trace()
+        {
+            return (int)SecT113Field.Trace(x);
+        }
+
         public override ECFieldElement Invert()
         {
             ulong[] z = Nat128.Create64();
diff --git a/crypto/src/math/ec/custom/sec/SecT131FieldElement.cs b/crypto/src/math/ec/custom/sec/SecT131FieldElement.cs
index c38e8eb0a..f96c7ca39 100644
--- a/crypto/src/math/ec/custom/sec/SecT131FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecT131FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecT131FieldElement
-        : ECFieldElement
+        : AbstractF2mFieldElement
     {
         protected internal readonly ulong[] x;
 
@@ -150,6 +150,11 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
             return new SecT131FieldElement(z);
         }
 
+        public override int Trace()
+        {
+            return (int)SecT131Field.Trace(x);
+        }
+
         public override ECFieldElement Invert()
         {
             ulong[] z = Nat192.Create64();
diff --git a/crypto/src/math/ec/custom/sec/SecT163FieldElement.cs b/crypto/src/math/ec/custom/sec/SecT163FieldElement.cs
index 07bd07652..903645999 100644
--- a/crypto/src/math/ec/custom/sec/SecT163FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecT163FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecT163FieldElement
-        : ECFieldElement
+        : AbstractF2mFieldElement
     {
         protected internal readonly ulong[] x;
 
@@ -150,6 +150,11 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
             return new SecT163FieldElement(z);
         }
 
+        public override int Trace()
+        {
+            return (int)SecT163Field.Trace(x);
+        }
+
         public override ECFieldElement Invert()
         {
             ulong[] z = Nat192.Create64();
diff --git a/crypto/src/math/ec/custom/sec/SecT193FieldElement.cs b/crypto/src/math/ec/custom/sec/SecT193FieldElement.cs
index d04e68d3f..9813bcb01 100644
--- a/crypto/src/math/ec/custom/sec/SecT193FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecT193FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecT193FieldElement
-        : ECFieldElement
+        : AbstractF2mFieldElement
     {
         protected internal readonly ulong[] x;
 
@@ -150,6 +150,11 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
             return new SecT193FieldElement(z);
         }
 
+        public override int Trace()
+        {
+            return (int)SecT193Field.Trace(x);
+        }
+
         public override ECFieldElement Invert()
         {
             ulong[] z = Nat256.Create64();
diff --git a/crypto/src/math/ec/custom/sec/SecT233FieldElement.cs b/crypto/src/math/ec/custom/sec/SecT233FieldElement.cs
index 64d09bd6d..fbfe35e13 100644
--- a/crypto/src/math/ec/custom/sec/SecT233FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecT233FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecT233FieldElement
-        : ECFieldElement
+        : AbstractF2mFieldElement
     {
         protected internal readonly ulong[] x;
 
@@ -150,6 +150,11 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
             return new SecT233FieldElement(z);
         }
 
+        public override int Trace()
+        {
+            return (int)SecT233Field.Trace(x);
+        }
+
         public override ECFieldElement Invert()
         {
             ulong[] z = Nat256.Create64();
diff --git a/crypto/src/math/ec/custom/sec/SecT239FieldElement.cs b/crypto/src/math/ec/custom/sec/SecT239FieldElement.cs
index 18563f746..b1b58e89b 100644
--- a/crypto/src/math/ec/custom/sec/SecT239FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecT239FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecT239FieldElement
-        : ECFieldElement
+        : AbstractF2mFieldElement
     {
         protected internal readonly ulong[] x;
 
@@ -150,6 +150,11 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
             return new SecT239FieldElement(z);
         }
 
+        public override int Trace()
+        {
+            return (int)SecT239Field.Trace(x);
+        }
+
         public override ECFieldElement Invert()
         {
             ulong[] z = Nat256.Create64();
diff --git a/crypto/src/math/ec/custom/sec/SecT283FieldElement.cs b/crypto/src/math/ec/custom/sec/SecT283FieldElement.cs
index b054bedfb..c1bb2e30c 100644
--- a/crypto/src/math/ec/custom/sec/SecT283FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecT283FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecT283FieldElement
-        : ECFieldElement
+        : AbstractF2mFieldElement
     {
         protected internal readonly ulong[] x;
 
@@ -150,6 +150,11 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
             return new SecT283FieldElement(z);
         }
 
+        public override int Trace()
+        {
+            return (int)SecT283Field.Trace(x);
+        }
+
         public override ECFieldElement Invert()
         {
             ulong[] z = Nat320.Create64();
diff --git a/crypto/src/math/ec/custom/sec/SecT409FieldElement.cs b/crypto/src/math/ec/custom/sec/SecT409FieldElement.cs
index 7076905bb..68a63312d 100644
--- a/crypto/src/math/ec/custom/sec/SecT409FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecT409FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecT409FieldElement
-        : ECFieldElement
+        : AbstractF2mFieldElement
     {
         protected internal readonly ulong[] x;
 
@@ -150,6 +150,11 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
             return new SecT409FieldElement(z);
         }
 
+        public override int Trace()
+        {
+            return (int)SecT409Field.Trace(x);
+        }
+
         public override ECFieldElement Invert()
         {
             ulong[] z = Nat448.Create64();
diff --git a/crypto/src/math/ec/custom/sec/SecT571FieldElement.cs b/crypto/src/math/ec/custom/sec/SecT571FieldElement.cs
index 5f28c01be..c9f3aa5c0 100644
--- a/crypto/src/math/ec/custom/sec/SecT571FieldElement.cs
+++ b/crypto/src/math/ec/custom/sec/SecT571FieldElement.cs
@@ -6,7 +6,7 @@ using Org.BouncyCastle.Utilities;
 namespace Org.BouncyCastle.Math.EC.Custom.Sec
 {
     internal class SecT571FieldElement
-        : ECFieldElement
+        : AbstractF2mFieldElement
     {
         protected internal readonly ulong[] x;
 
@@ -150,6 +150,11 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec
             return new SecT571FieldElement(z);
         }
 
+        public override int Trace()
+        {
+            return (int)SecT571Field.Trace(x);
+        }
+
         public override ECFieldElement Invert()
         {
             ulong[] z = Nat576.Create64();
diff --git a/crypto/src/math/ec/multiplier/AbstractECMultiplier.cs b/crypto/src/math/ec/multiplier/AbstractECMultiplier.cs
index 517881323..c2580c852 100644
--- a/crypto/src/math/ec/multiplier/AbstractECMultiplier.cs
+++ b/crypto/src/math/ec/multiplier/AbstractECMultiplier.cs
@@ -16,9 +16,14 @@
              * Although the various multipliers ought not to produce invalid output under normal
              * circumstances, a final check here is advised to guard against fault attacks.
              */
-            return ECAlgorithms.ValidatePoint(result);
+            return CheckResult(result);
         }
 
         protected abstract ECPoint MultiplyPositive(ECPoint p, BigInteger k);
+
+        protected virtual ECPoint CheckResult(ECPoint p)
+        {
+            return ECAlgorithms.ImplCheckResult(p);
+        }
     }
 }
diff --git a/crypto/src/math/ec/multiplier/FixedPointCombMultiplier.cs b/crypto/src/math/ec/multiplier/FixedPointCombMultiplier.cs
index adaedb809..505832442 100644
--- a/crypto/src/math/ec/multiplier/FixedPointCombMultiplier.cs
+++ b/crypto/src/math/ec/multiplier/FixedPointCombMultiplier.cs
@@ -52,11 +52,5 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
 
             return R.Add(info.Offset);
         }
-
-        [Obsolete("Is no longer used; remove any overrides in subclasses.")]
-        protected virtual int GetWidthForCombSize(int combSize)
-        {
-            return combSize > 257 ? 6 : 5;
-        }
     }
 }
diff --git a/crypto/src/math/ec/multiplier/FixedPointPreCompInfo.cs b/crypto/src/math/ec/multiplier/FixedPointPreCompInfo.cs
index 4c0b404df..5d6af9e5d 100644
--- a/crypto/src/math/ec/multiplier/FixedPointPreCompInfo.cs
+++ b/crypto/src/math/ec/multiplier/FixedPointPreCompInfo.cs
@@ -11,13 +11,6 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
         protected ECPoint m_offset = null;
 
         /**
-         * Array holding the precomputed <code>ECPoint</code>s used for a fixed
-         * point multiplication.
-         */
-        [Obsolete("Will be removed")]
-		protected ECPoint[] m_preComp = null;
-
-        /**
          * Lookup table for the precomputed <code>ECPoint</code>s used for a fixed point multiplication.
          */
         protected ECLookupTable m_lookupTable = null;
@@ -41,13 +34,6 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
 			set { this.m_offset = value; }
 		}
 
-        [Obsolete("Use 'LookupTable' property instead.")]
-        public virtual ECPoint[] PreComp
-        {
-            get { return m_preComp; }
-            set { this.m_preComp = value; }
-        }
-
         public virtual int Width
         {
             get { return m_width; }
diff --git a/crypto/src/math/ec/multiplier/FixedPointUtilities.cs b/crypto/src/math/ec/multiplier/FixedPointUtilities.cs
index cc7203314..88f178e24 100644
--- a/crypto/src/math/ec/multiplier/FixedPointUtilities.cs
+++ b/crypto/src/math/ec/multiplier/FixedPointUtilities.cs
@@ -14,36 +14,40 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
 
         public static FixedPointPreCompInfo GetFixedPointPreCompInfo(PreCompInfo preCompInfo)
         {
-            if ((preCompInfo != null) && (preCompInfo is FixedPointPreCompInfo))
-            {
-                return (FixedPointPreCompInfo)preCompInfo;
-            }
-
-            return new FixedPointPreCompInfo();
+            return preCompInfo as FixedPointPreCompInfo;
         }
 
-        [Obsolete("Use 'Precompute(ECPoint)' instead, as minWidth parameter is now ignored")]
-        public static FixedPointPreCompInfo Precompute(ECPoint p, int minWidth)
+        public static FixedPointPreCompInfo Precompute(ECPoint p)
         {
-            return Precompute(p);
+            return (FixedPointPreCompInfo)p.Curve.Precompute(p, PRECOMP_NAME, new FixedPointCallback(p));
         }
 
-        public static FixedPointPreCompInfo Precompute(ECPoint p)
+        private class FixedPointCallback
+            : IPreCompCallback
         {
-            ECCurve c = p.Curve;
-            int minWidth = GetCombSize(c) > 257 ? 6 : 5;
+            private readonly ECPoint m_p;
 
-            int n = 1 << minWidth;
-            FixedPointPreCompInfo info = GetFixedPointPreCompInfo(c.GetPreCompInfo(p, PRECOMP_NAME));
-            ECPoint[] lookupTable = info.PreComp;
+            internal FixedPointCallback(ECPoint p)
+            {
+                this.m_p = p;
+            }
 
-            if (lookupTable == null || lookupTable.Length < n)
+            public PreCompInfo Precompute(PreCompInfo existing)
             {
-                int bits = GetCombSize(c);
+                FixedPointPreCompInfo existingFP = (existing is FixedPointPreCompInfo) ? (FixedPointPreCompInfo)existing : null;
+
+                ECCurve c = m_p.Curve;
+                int bits = FixedPointUtilities.GetCombSize(c);
+                int minWidth = bits > 250 ? 6 : 5;
+                int n = 1 << minWidth;
+
+                if (CheckExisting(existingFP, n))
+                    return existingFP;
+
                 int d = (bits + minWidth - 1) / minWidth;
 
                 ECPoint[] pow2Table = new ECPoint[minWidth + 1];
-                pow2Table[0] = p;
+                pow2Table[0] = m_p;
                 for (int i = 1; i < minWidth; ++i)
                 {
                     pow2Table[i] = pow2Table[i - 1].TimesPow2(d);
@@ -53,8 +57,8 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
                 pow2Table[minWidth] = pow2Table[0].Subtract(pow2Table[1]);
 
                 c.NormalizeAll(pow2Table);
-    
-                lookupTable = new ECPoint[n];
+
+                ECPoint[] lookupTable = new ECPoint[n];
                 lookupTable[0] = pow2Table[0];
 
                 for (int bit = minWidth - 1; bit >= 0; --bit)
@@ -70,15 +74,22 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
 
                 c.NormalizeAll(lookupTable);
 
-                info.LookupTable = c.CreateCacheSafeLookupTable(lookupTable, 0, lookupTable.Length);
-                info.Offset = pow2Table[minWidth];
-                info.PreComp = lookupTable;
-                info.Width = minWidth;
+                FixedPointPreCompInfo result = new FixedPointPreCompInfo();
+                result.LookupTable = c.CreateCacheSafeLookupTable(lookupTable, 0, lookupTable.Length);
+                result.Offset = pow2Table[minWidth];
+                result.Width = minWidth;
+                return result;
+            }
 
-                c.SetPreCompInfo(p, PRECOMP_NAME, info);
+            private bool CheckExisting(FixedPointPreCompInfo existingFP, int n)
+            {
+                return existingFP != null && CheckTable(existingFP.LookupTable, n);
             }
 
-            return info;
+            private bool CheckTable(ECLookupTable table, int n)
+            {
+                return table != null && table.Size >= n;
+            }
         }
     }
 }
diff --git a/crypto/src/math/ec/multiplier/IPreCompCallback.cs b/crypto/src/math/ec/multiplier/IPreCompCallback.cs
new file mode 100644
index 000000000..e64ae834d
--- /dev/null
+++ b/crypto/src/math/ec/multiplier/IPreCompCallback.cs
@@ -0,0 +1,9 @@
+using System;
+
+namespace Org.BouncyCastle.Math.EC.Multiplier
+{
+    public interface IPreCompCallback
+    {
+        PreCompInfo Precompute(PreCompInfo existing);
+    }
+}
diff --git a/crypto/src/math/ec/multiplier/ValidityPreCompInfo.cs b/crypto/src/math/ec/multiplier/ValidityPreCompInfo.cs
new file mode 100644
index 000000000..7ec2cbb95
--- /dev/null
+++ b/crypto/src/math/ec/multiplier/ValidityPreCompInfo.cs
@@ -0,0 +1,44 @@
+using System;
+
+namespace Org.BouncyCastle.Math.EC.Multiplier
+{
+    internal class ValidityPreCompInfo
+        : PreCompInfo
+    {
+        internal static readonly string PRECOMP_NAME = "bc_validity";
+
+        private bool failed = false;
+        private bool curveEquationPassed = false;
+        private bool orderPassed = false;
+
+        internal bool HasFailed()
+        {
+            return failed;
+        }
+
+        internal void ReportFailed()
+        {
+            failed = true;
+        }
+
+        internal bool HasCurveEquationPassed()
+        {
+            return curveEquationPassed;
+        }
+
+        internal void ReportCurveEquationPassed()
+        {
+            curveEquationPassed = true;
+        }
+
+        internal bool HasOrderPassed()
+        {
+            return orderPassed;
+        }
+
+        internal void ReportOrderPassed()
+        {
+            orderPassed = true;
+        }
+    }
+}
diff --git a/crypto/src/math/ec/multiplier/WNafUtilities.cs b/crypto/src/math/ec/multiplier/WNafUtilities.cs
index 7d565dfbd..e893abd49 100644
--- a/crypto/src/math/ec/multiplier/WNafUtilities.cs
+++ b/crypto/src/math/ec/multiplier/WNafUtilities.cs
@@ -287,12 +287,7 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
 
         public static WNafPreCompInfo GetWNafPreCompInfo(PreCompInfo preCompInfo)
         {
-            if ((preCompInfo != null) && (preCompInfo is WNafPreCompInfo))
-            {
-                return (WNafPreCompInfo)preCompInfo;
-            }
-
-            return new WNafPreCompInfo();
+            return preCompInfo as WNafPreCompInfo;
         }
 
         /**
@@ -333,106 +328,178 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
             WNafPreCompInfo wnafPreCompP = Precompute(p, width, includeNegated);
 
             ECPoint q = pointMap.Map(p);
-            WNafPreCompInfo wnafPreCompQ = GetWNafPreCompInfo(c.GetPreCompInfo(q, PRECOMP_NAME));
+            c.Precompute(q, PRECOMP_NAME, new MapPointCallback(wnafPreCompP, includeNegated, pointMap));
+            return q;
+        }
 
-            ECPoint twiceP = wnafPreCompP.Twice;
-            if (twiceP != null)
-            {
-                ECPoint twiceQ = pointMap.Map(twiceP);
-                wnafPreCompQ.Twice = twiceQ;
-            }
+        public static WNafPreCompInfo Precompute(ECPoint p, int width, bool includeNegated)
+        {
+            return (WNafPreCompInfo)p.Curve.Precompute(p, PRECOMP_NAME, new WNafCallback(p, width, includeNegated));
+        }
+
+        private static byte[] Trim(byte[] a, int length)
+        {
+            byte[] result = new byte[length];
+            Array.Copy(a, 0, result, 0, result.Length);
+            return result;
+        }
+
+        private static int[] Trim(int[] a, int length)
+        {
+            int[] result = new int[length];
+            Array.Copy(a, 0, result, 0, result.Length);
+            return result;
+        }
+
+        private static ECPoint[] ResizeTable(ECPoint[] a, int length)
+        {
+            ECPoint[] result = new ECPoint[length];
+            Array.Copy(a, 0, result, 0, a.Length);
+            return result;
+        }
+
+        private class MapPointCallback
+            : IPreCompCallback
+        {
+            private readonly WNafPreCompInfo m_wnafPreCompP;
+            private readonly bool m_includeNegated;
+            private readonly ECPointMap m_pointMap;
 
-            ECPoint[] preCompP = wnafPreCompP.PreComp;
-            ECPoint[] preCompQ = new ECPoint[preCompP.Length];
-            for (int i = 0; i < preCompP.Length; ++i)
+            internal MapPointCallback(WNafPreCompInfo wnafPreCompP, bool includeNegated, ECPointMap pointMap)
             {
-                preCompQ[i] = pointMap.Map(preCompP[i]);
+                this.m_wnafPreCompP = wnafPreCompP;
+                this.m_includeNegated = includeNegated;
+                this.m_pointMap = pointMap;
             }
-            wnafPreCompQ.PreComp = preCompQ;
 
-            if (includeNegated)
+            public PreCompInfo Precompute(PreCompInfo existing)
             {
-                ECPoint[] preCompNegQ = new ECPoint[preCompQ.Length];
-                for (int i = 0; i < preCompNegQ.Length; ++i)
+                WNafPreCompInfo result = new WNafPreCompInfo();
+
+                ECPoint twiceP = m_wnafPreCompP.Twice;
+                if (twiceP != null)
                 {
-                    preCompNegQ[i] = preCompQ[i].Negate();
+                    ECPoint twiceQ = m_pointMap.Map(twiceP);
+                    result.Twice = twiceQ;
                 }
-                wnafPreCompQ.PreCompNeg = preCompNegQ;
-            }
 
-            c.SetPreCompInfo(q, PRECOMP_NAME, wnafPreCompQ);
+                ECPoint[] preCompP = m_wnafPreCompP.PreComp;
+                ECPoint[] preCompQ = new ECPoint[preCompP.Length];
+                for (int i = 0; i < preCompP.Length; ++i)
+                {
+                    preCompQ[i] = m_pointMap.Map(preCompP[i]);
+                }
+                result.PreComp = preCompQ;
 
-            return q;
+                if (m_includeNegated)
+                {
+                    ECPoint[] preCompNegQ = new ECPoint[preCompQ.Length];
+                    for (int i = 0; i < preCompNegQ.Length; ++i)
+                    {
+                        preCompNegQ[i] = preCompQ[i].Negate();
+                    }
+                    result.PreCompNeg = preCompNegQ;
+                }
+
+                return result;
+            }
         }
 
-        public static WNafPreCompInfo Precompute(ECPoint p, int width, bool includeNegated)
+        private class WNafCallback
+            : IPreCompCallback
         {
-            ECCurve c = p.Curve;
-            WNafPreCompInfo wnafPreCompInfo = GetWNafPreCompInfo(c.GetPreCompInfo(p, PRECOMP_NAME));
+            private readonly ECPoint m_p;
+            private readonly int m_width;
+            private readonly bool m_includeNegated;
 
-            int iniPreCompLen = 0, reqPreCompLen = 1 << System.Math.Max(0, width - 2);
-
-            ECPoint[] preComp = wnafPreCompInfo.PreComp;
-            if (preComp == null)
+            internal WNafCallback(ECPoint p, int width, bool includeNegated)
             {
-                preComp = EMPTY_POINTS;
-            }
-            else
-            {
-                iniPreCompLen = preComp.Length;
+                this.m_p = p;
+                this.m_width = width;
+                this.m_includeNegated = includeNegated;
             }
 
-            if (iniPreCompLen < reqPreCompLen)
+            public PreCompInfo Precompute(PreCompInfo existing)
             {
-                preComp = ResizeTable(preComp, reqPreCompLen);
+                WNafPreCompInfo existingWNaf = existing as WNafPreCompInfo;
+
+                int reqPreCompLen = 1 << System.Math.Max(0, m_width - 2);
+
+                if (CheckExisting(existingWNaf, reqPreCompLen, m_includeNegated))
+                    return existingWNaf;
 
-                if (reqPreCompLen == 1)
+                ECCurve c = m_p.Curve;
+                ECPoint[] preComp = null, preCompNeg = null;
+                ECPoint twiceP = null;
+
+                if (existingWNaf != null)
+                {
+                    preComp = existingWNaf.PreComp;
+                    preCompNeg = existingWNaf.PreCompNeg;
+                    twiceP = existingWNaf.Twice;
+                }
+
+                int iniPreCompLen = 0;
+                if (preComp == null)
                 {
-                    preComp[0] = p.Normalize();
+                    preComp = EMPTY_POINTS;
                 }
                 else
                 {
-                    int curPreCompLen = iniPreCompLen;
-                    if (curPreCompLen == 0)
-                    {
-                        preComp[0] = p;
-                        curPreCompLen = 1;
-                    }
+                    iniPreCompLen = preComp.Length;
+                }
 
-                    ECFieldElement iso = null;
+                if (iniPreCompLen < reqPreCompLen)
+                {
+                    preComp = WNafUtilities.ResizeTable(preComp, reqPreCompLen);
 
-                    if (reqPreCompLen == 2)
+                    if (reqPreCompLen == 1)
                     {
-                        preComp[1] = p.ThreeTimes();
+                        preComp[0] = m_p.Normalize();
                     }
                     else
                     {
-                        ECPoint twiceP = wnafPreCompInfo.Twice, last = preComp[curPreCompLen - 1];
-                        if (twiceP == null)
+                        int curPreCompLen = iniPreCompLen;
+                        if (curPreCompLen == 0)
+                        {
+                            preComp[0] = m_p;
+                            curPreCompLen = 1;
+                        }
+
+                        ECFieldElement iso = null;
+
+                        if (reqPreCompLen == 2)
+                        {
+                            preComp[1] = m_p.ThreeTimes();
+                        }
+                        else
                         {
-                            twiceP = preComp[0].Twice();
-                            wnafPreCompInfo.Twice = twiceP;
-
-                            /*
-                             * For Fp curves with Jacobian projective coordinates, use a (quasi-)isomorphism
-                             * where 'twiceP' is "affine", so that the subsequent additions are cheaper. This
-                             * also requires scaling the initial point's X, Y coordinates, and reversing the
-                             * isomorphism as part of the subsequent normalization.
-                             * 
-                             *  NOTE: The correctness of this optimization depends on:
-                             *      1) additions do not use the curve's A, B coefficients.
-                             *      2) no special cases (i.e. Q +/- Q) when calculating 1P, 3P, 5P, ...
-                             */
-                            if (!twiceP.IsInfinity && ECAlgorithms.IsFpCurve(c) && c.FieldSize >= 64)
+                            ECPoint isoTwiceP = twiceP, last = preComp[curPreCompLen - 1];
+                            if (isoTwiceP == null)
                             {
-                                switch (c.CoordinateSystem)
+                                isoTwiceP = preComp[0].Twice();
+                                twiceP = isoTwiceP;
+
+                                /*
+                                 * For Fp curves with Jacobian projective coordinates, use a (quasi-)isomorphism
+                                 * where 'twiceP' is "affine", so that the subsequent additions are cheaper. This
+                                 * also requires scaling the initial point's X, Y coordinates, and reversing the
+                                 * isomorphism as part of the subsequent normalization.
+                                 * 
+                                 *  NOTE: The correctness of this optimization depends on:
+                                 *      1) additions do not use the curve's A, B coefficients.
+                                 *      2) no special cases (i.e. Q +/- Q) when calculating 1P, 3P, 5P, ...
+                                 */
+                                if (!twiceP.IsInfinity && ECAlgorithms.IsFpCurve(c) && c.FieldSize >= 64)
                                 {
+                                    switch (c.CoordinateSystem)
+                                    {
                                     case ECCurve.COORD_JACOBIAN:
                                     case ECCurve.COORD_JACOBIAN_CHUDNOVSKY:
                                     case ECCurve.COORD_JACOBIAN_MODIFIED:
                                     {
                                         iso = twiceP.GetZCoord(0);
-                                        twiceP = c.CreatePoint(twiceP.XCoord.ToBigInteger(),
+                                        isoTwiceP = c.CreatePoint(twiceP.XCoord.ToBigInteger(),
                                             twiceP.YCoord.ToBigInteger());
 
                                         ECFieldElement iso2 = iso.Square(), iso3 = iso2.Multiply(iso);
@@ -444,81 +511,69 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
                                         }
                                         break;
                                     }
+                                    }
                                 }
                             }
-                        }
 
-                        while (curPreCompLen < reqPreCompLen)
-                        {
-                            /*
-                             * Compute the new ECPoints for the precomputation array. The values 1, 3,
-                             * 5, ..., 2^(width-1)-1 times p are computed
-                             */
-                            preComp[curPreCompLen++] = last = last.Add(twiceP);
+                            while (curPreCompLen < reqPreCompLen)
+                            {
+                                /*
+                                 * Compute the new ECPoints for the precomputation array. The values 1, 3,
+                                 * 5, ..., 2^(width-1)-1 times p are computed
+                                 */
+                                preComp[curPreCompLen++] = last = last.Add(isoTwiceP);
+                            }
                         }
-                    }
 
-                    /*
-                     * Having oft-used operands in affine form makes operations faster.
-                     */
-                    c.NormalizeAll(preComp, iniPreCompLen, reqPreCompLen - iniPreCompLen, iso);
+                        /*
+                         * Having oft-used operands in affine form makes operations faster.
+                         */
+                        c.NormalizeAll(preComp, iniPreCompLen, reqPreCompLen - iniPreCompLen, iso);
+                    }
                 }
-            }
-
-            wnafPreCompInfo.PreComp = preComp;
-
-            if (includeNegated)
-            {
-                ECPoint[] preCompNeg = wnafPreCompInfo.PreCompNeg;
 
-                int pos;
-                if (preCompNeg == null)
-                {
-                    pos = 0;
-                    preCompNeg = new ECPoint[reqPreCompLen]; 
-                }
-                else
+                if (m_includeNegated)
                 {
-                    pos = preCompNeg.Length;
-                    if (pos < reqPreCompLen)
+                    int pos;
+                    if (preCompNeg == null)
                     {
-                        preCompNeg = ResizeTable(preCompNeg, reqPreCompLen);
+                        pos = 0;
+                        preCompNeg = new ECPoint[reqPreCompLen]; 
+                    }
+                    else
+                    {
+                        pos = preCompNeg.Length;
+                        if (pos < reqPreCompLen)
+                        {
+                            preCompNeg = WNafUtilities.ResizeTable(preCompNeg, reqPreCompLen);
+                        }
                     }
-                }
 
-                while (pos < reqPreCompLen)
-                {
-                    preCompNeg[pos] = preComp[pos].Negate();
-                    ++pos;
+                    while (pos < reqPreCompLen)
+                    {
+                        preCompNeg[pos] = preComp[pos].Negate();
+                        ++pos;
+                    }
                 }
 
-                wnafPreCompInfo.PreCompNeg = preCompNeg;
+                WNafPreCompInfo result = new WNafPreCompInfo();
+                result.PreComp = preComp;
+                result.PreCompNeg = preCompNeg;
+                result.Twice = twiceP;
+                return result;
             }
 
-            c.SetPreCompInfo(p, PRECOMP_NAME, wnafPreCompInfo);
-
-            return wnafPreCompInfo;
-        }
-
-        private static byte[] Trim(byte[] a, int length)
-        {
-            byte[] result = new byte[length];
-            Array.Copy(a, 0, result, 0, result.Length);
-            return result;
-        }
-
-        private static int[] Trim(int[] a, int length)
-        {
-            int[] result = new int[length];
-            Array.Copy(a, 0, result, 0, result.Length);
-            return result;
-        }
+            private bool CheckExisting(WNafPreCompInfo existingWNaf, int reqPreCompLen, bool includeNegated)
+            {
+                return existingWNaf != null
+                    && CheckTable(existingWNaf.PreComp, reqPreCompLen)
+                    && (!includeNegated || CheckTable(existingWNaf.PreCompNeg, reqPreCompLen));
+            }
 
-        private static ECPoint[] ResizeTable(ECPoint[] a, int length)
-        {
-            ECPoint[] result = new ECPoint[length];
-            Array.Copy(a, 0, result, 0, a.Length);
-            return result;
+            private bool CheckTable(ECPoint[] table, int reqLen)
+            {
+                return table != null && table.Length >= reqLen;
+            }
         }
     }
 }
diff --git a/crypto/src/math/ec/multiplier/WTauNafMultiplier.cs b/crypto/src/math/ec/multiplier/WTauNafMultiplier.cs
index 1e7ddae91..4dce54440 100644
--- a/crypto/src/math/ec/multiplier/WTauNafMultiplier.cs
+++ b/crypto/src/math/ec/multiplier/WTauNafMultiplier.cs
@@ -36,7 +36,7 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
 
             ZTauElement rho = Tnaf.PartModReduction(k, m, a, s, mu, (sbyte)10);
 
-            return MultiplyWTnaf(p, rho, curve.GetPreCompInfo(p, PRECOMP_NAME), a, mu);
+            return MultiplyWTnaf(p, rho, a, mu);
         }
 
         /**
@@ -50,7 +50,7 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
         * @return <code>p</code> multiplied by <code>&#955;</code>.
         */
         private AbstractF2mPoint MultiplyWTnaf(AbstractF2mPoint p, ZTauElement lambda,
-            PreCompInfo preCompInfo, sbyte a, sbyte mu)
+            sbyte a, sbyte mu)
         {
             ZTauElement[] alpha = (a == 0) ? Tnaf.Alpha0 : Tnaf.Alpha1;
 
@@ -59,7 +59,7 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
             sbyte[]u = Tnaf.TauAdicWNaf(mu, lambda, Tnaf.Width,
                 BigInteger.ValueOf(Tnaf.Pow2Width), tw, alpha);
 
-            return MultiplyFromWTnaf(p, u, preCompInfo);
+            return MultiplyFromWTnaf(p, u);
         }
         
         /**
@@ -71,24 +71,14 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
         * @param u The the WTNAF of <code>&#955;</code>..
         * @return <code>&#955; * p</code>
         */
-        private static AbstractF2mPoint MultiplyFromWTnaf(AbstractF2mPoint p, sbyte[] u, PreCompInfo preCompInfo)
+        private static AbstractF2mPoint MultiplyFromWTnaf(AbstractF2mPoint p, sbyte[] u)
         {
             AbstractF2mCurve curve = (AbstractF2mCurve)p.Curve;
             sbyte a = (sbyte)curve.A.ToBigInteger().IntValue;
 
-            AbstractF2mPoint[] pu;
-            if ((preCompInfo == null) || !(preCompInfo is WTauNafPreCompInfo))
-            {
-                pu = Tnaf.GetPreComp(p, a);
-
-                WTauNafPreCompInfo pre = new WTauNafPreCompInfo();
-                pre.PreComp = pu;
-                curve.SetPreCompInfo(p, PRECOMP_NAME, pre);
-            }
-            else
-            {
-                pu = ((WTauNafPreCompInfo)preCompInfo).PreComp;
-            }
+            WTauNafCallback callback = new WTauNafCallback(p, a);
+            WTauNafPreCompInfo preCompInfo = (WTauNafPreCompInfo)curve.Precompute(p, PRECOMP_NAME, callback);
+            AbstractF2mPoint[] pu = preCompInfo.PreComp;
 
             // TODO Include negations in precomp (optionally) and use from here
             AbstractF2mPoint[] puNeg = new AbstractF2mPoint[pu.Length];
@@ -121,5 +111,28 @@ namespace Org.BouncyCastle.Math.EC.Multiplier
             }
             return q;
         }
+
+        private class WTauNafCallback
+            : IPreCompCallback
+        {
+            private readonly AbstractF2mPoint m_p;
+            private readonly sbyte m_a;
+
+            internal WTauNafCallback(AbstractF2mPoint p, sbyte a)
+            {
+                this.m_p = p;
+                this.m_a = a;
+            }
+
+            public PreCompInfo Precompute(PreCompInfo existing)
+            {
+                if (existing is WTauNafPreCompInfo)
+                    return existing;
+
+                WTauNafPreCompInfo result = new WTauNafPreCompInfo();
+                result.PreComp = Tnaf.GetPreComp(m_p, m_a);
+                return result;
+            }
+        }
     }
 }
diff --git a/crypto/src/math/ec/rfc7748/X25519.cs b/crypto/src/math/ec/rfc7748/X25519.cs
index 8c52a21ac..38bc9c1f1 100644
--- a/crypto/src/math/ec/rfc7748/X25519.cs
+++ b/crypto/src/math/ec/rfc7748/X25519.cs
@@ -10,10 +10,10 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
         private const int C_A24 = (C_A + 2)/4;
 
         // 0x1
-        //private static readonly int[] S_x = new int[] { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
+        //private static readonly int[] S_x = { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
 
         // 0x215132111D8354CB52385F46DCA2B71D440F6A51EB4D1207816B1E0137D48290
-        private static readonly int[] PsubS_x = new int[]{ 0x03D48290, 0x02C7804D, 0x01207816, 0x028F5A68, 0x00881ED4, 0x00A2B71D,
+        private static readonly int[] PsubS_x = { 0x03D48290, 0x02C7804D, 0x01207816, 0x028F5A68, 0x00881ED4, 0x00A2B71D,
             0x0217D1B7, 0x014CB523, 0x0088EC1A, 0x0042A264 };
 
         private static int[] precompBase = null;
diff --git a/crypto/src/math/ec/rfc7748/X25519Field.cs b/crypto/src/math/ec/rfc7748/X25519Field.cs
index 282f41628..fd5599657 100644
--- a/crypto/src/math/ec/rfc7748/X25519Field.cs
+++ b/crypto/src/math/ec/rfc7748/X25519Field.cs
@@ -11,6 +11,9 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
         private const int M25 = 0x01FFFFFF;
         private const int M26 = 0x03FFFFFF;
 
+        private static readonly int[] RootNegOne = { 0x020EA0B0, 0x0386C9D2, 0x00478C4E, 0x0035697F, 0x005E8630,
+            0x01FBD7A7, 0x0340264F, 0x01F0B2B4, 0x00027E0E, 0x00570649 };
+
         private X25519Field() {}
 
         public static void Add(int[] x, int[] y, int[] z)
@@ -21,6 +24,16 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             }
         }
 
+        public static void AddOne(int[] z)
+        {
+            z[0] += 1;
+        }
+
+        public static void AddOne(int[] z, int zOff)
+        {
+            z[zOff] += 1;
+        }
+
         public static void Apm(int[] x, int[] y, int[] zp, int[] zm)
         {
             for (int i = 0; i < Size; ++i)
@@ -54,6 +67,17 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             z[5] = z5; z[6] = z6; z[7] = z7; z[8] = z8; z[9] = z9;
         }
 
+        public static void CNegate(int negate, int[] z)
+        {
+            Debug.Assert(negate >> 1 == 0);
+
+            int mask = 0 - negate;
+            for (int i = 0; i < Size; ++i)
+            {
+                z[i] = (z[i] ^ mask) - mask;
+            }
+        }
+
         public static void Copy(int[] x, int xOff, int[] z, int zOff)
         {
             for (int i = 0; i < Size; ++i)
@@ -67,6 +91,11 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             return new int[Size];
         }
 
+        public static int[] CreateTable(int n)
+        {
+            return new int[Size * n];
+        }
+
         public static void CSwap(int swap, int[] a, int[] b)
         {
             Debug.Assert(swap >> 1 == 0);
@@ -143,24 +172,23 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             // (250 1s) (1 0s) (1 1s) (1 0s) (2 1s)
             // Addition chain: [1] [2] 3 5 10 15 25 50 75 125 [250]
 
-            int[] x2 = Create();    Sqr(x, x2);             Mul(x, x2, x2);
-            int[] x3 = Create();    Sqr(x2, x3);            Mul(x, x3, x3);
-            int[] x5 = x3;          Sqr(x3, 2, x5);         Mul(x2, x5, x5);
-            int[] x10 = Create();   Sqr(x5, 5, x10);        Mul(x5, x10, x10);
-            int[] x15 = Create();   Sqr(x10, 5, x15);       Mul(x5, x15, x15);
-            int[] x25 = x5;         Sqr(x15, 10, x25);      Mul(x10, x25, x25);
-            int[] x50 = x10;        Sqr(x25, 25, x50);      Mul(x25, x50, x50);
-            int[] x75 = x15;        Sqr(x50, 25, x75);      Mul(x25, x75, x75);
-            int[] x125 = x25;       Sqr(x75, 50, x125);     Mul(x50, x125, x125);
-            int[] x250 = x50;       Sqr(x125, 125, x250);   Mul(x125, x250, x250);
-
-            int[] t = x125;
-            Sqr(x250, 2, t);
-            Mul(t, x, t);
+            int[] x2 = Create();
+            int[] t = Create();
+            PowPm5d8(x, x2, t);
             Sqr(t, 3, t);
             Mul(t, x2, z);
         }
 
+        public static bool IsZeroVar(int[] x)
+        {
+            int d = 0;
+            for (int i = 0; i < Size; ++i)
+            {
+                d |= x[i];
+            }
+            return d == 0;
+        }
+
         public static void Mul(int[] x, int y, int[] z)
         {
             int x0 = x[0], x1 = x[1], x2 = x[2], x3 = x[3], x4 = x[4];
@@ -345,6 +373,14 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             z[9]     = z9 + (int)t;
         }
 
+        public static void Negate(int[] x, int[] z)
+        {
+            for (int i = 0; i < Size; ++i)
+            {
+                z[i] = -x[i];
+            }
+        }
+
         public static void Normalize(int[] z)
         {
             int x = (z[9] >> 23) & 1;
@@ -353,6 +389,37 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             Debug.Assert(z[9] >> 24 == 0);
         }
 
+        public static void One(int[] z)
+        {
+            z[0] = 1;
+            for (int i = 1; i < Size; ++i)
+            {
+                z[i] = 0;
+            }
+        }
+
+        private static void PowPm5d8(int[] x, int[] rx2, int[] rz)
+        {
+            // z = x^((p-5)/8) = x^FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFD
+            // (250 1s) (1 0s) (1 1s)
+            // Addition chain: [1] 2 3 5 10 15 25 50 75 125 [250]
+
+            int[] x2 = rx2;         Sqr(x, x2);             Mul(x, x2, x2);
+            int[] x3 = Create();    Sqr(x2, x3);            Mul(x, x3, x3);
+            int[] x5 = x3;          Sqr(x3, 2, x5);         Mul(x2, x5, x5);
+            int[] x10 = Create();   Sqr(x5, 5, x10);        Mul(x5, x10, x10);
+            int[] x15 = Create();   Sqr(x10, 5, x15);       Mul(x5, x15, x15);
+            int[] x25 = x5;         Sqr(x15, 10, x25);      Mul(x10, x25, x25);
+            int[] x50 = x10;        Sqr(x25, 25, x50);      Mul(x25, x50, x50);
+            int[] x75 = x15;        Sqr(x50, 25, x75);      Mul(x25, x75, x75);
+            int[] x125 = x25;       Sqr(x75, 50, x125);     Mul(x50, x125, x125);
+            int[] x250 = x50;       Sqr(x125, 125, x250);   Mul(x125, x250, x250);
+
+            int[] t = x125;
+            Sqr(x250, 2, t);
+            Mul(t, x, rz);
+        }
+
         private static void Reduce(int[] z, int c)
         {
             int z9 = z[9], t = z9;
@@ -509,6 +576,45 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             }
         }
 
+        public static bool SqrtRatioVar(int[] u, int[] v, int[] z)
+        {
+            int[] uv3 = Create();
+            int[] uv7 = Create();
+
+            Mul(u, v, uv3);
+            Sqr(v, uv7);
+            Mul(uv3, uv7, uv3);
+            Sqr(uv7, uv7);
+            Mul(uv7, uv3, uv7);
+
+            int[] t = Create();
+            int[] x = Create();
+            PowPm5d8(uv7, t, x);
+            Mul(x, uv3, x);
+
+            int[] vx2 = Create();
+            Sqr(x, vx2);
+            Mul(vx2, v, vx2);
+
+            Sub(vx2, u, t);
+            Normalize(t);
+            if (IsZeroVar(t))
+            {
+                Copy(x, 0, z, 0);
+                return true;
+            }
+
+            Add(vx2, u, t);
+            Normalize(t);
+            if (IsZeroVar(t))
+            {
+                Mul(x, RootNegOne, z);
+                return true;
+            }
+
+            return false;
+        }
+
         public static void Sub(int[] x, int[] y, int[] z)
         {
             for (int i = 0; i < Size; ++i)
@@ -516,5 +622,18 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
                 z[i] = x[i] - y[i];
             }
         }
+
+        public static void SubOne(int[] z)
+        {
+            z[0] -= 1;
+        }
+
+        public static void Zero(int[] z)
+        {
+            for (int i = 0; i < Size; ++i)
+            {
+                z[i] = 0;
+            }
+        }
     }
 }
diff --git a/crypto/src/math/ec/rfc7748/X448.cs b/crypto/src/math/ec/rfc7748/X448.cs
index 8ded25a06..4e6e32879 100644
--- a/crypto/src/math/ec/rfc7748/X448.cs
+++ b/crypto/src/math/ec/rfc7748/X448.cs
@@ -10,14 +10,14 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
         private const uint C_A24 = (C_A + 2)/4;
 
         // 0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFE
-        private static readonly uint[] S_x = new uint[]{ 0x0FFFFFFEU, 0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFFU,
+        private static readonly uint[] S_x = { 0x0FFFFFFEU, 0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFFU,
             0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFEU, 0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFFU, 0x0FFFFFFFU,
             0x0FFFFFFFU };
 
         // 0xF0FAB725013244423ACF03881AFFEB7BDACDD1031C81B9672954459D84C1F823F1BD65643ACE1B5123AC33FF1C69BAF8ACB1197DC99D2720
-        private static readonly uint[] PsubS_x = new uint[]{ 0x099d2720U, 0x0b1197dcU, 0x09baf8acU, 0x033ff1c6U, 0x0b5123acU,
-            0x0643ace1U, 0x03f1bd65U, 0x084c1f82U, 0x0954459dU, 0x081b9672U, 0x0dd1031cU, 0x0eb7bdacU, 0x03881affU, 0x0423acf0U,
-            0x05013244U, 0x0f0fab72U };
+        private static readonly uint[] PsubS_x = { 0x099D2720U, 0x0B1197DCU, 0x09BAF8ACU, 0x033FF1C6U, 0x0B5123ACU,
+            0x0643ACE1U, 0x03F1BD65U, 0x084C1F82U, 0x0954459DU, 0x081B9672U, 0x0DD1031CU, 0x0EB7BDACU, 0x03881AFFU, 0x0423ACF0U,
+            0x05013244U, 0x0F0FAB72U };
 
         private static uint[] precompBase = null;
 
diff --git a/crypto/src/math/ec/rfc7748/X448Field.cs b/crypto/src/math/ec/rfc7748/X448Field.cs
index 0c44f1eb5..5a682714d 100644
--- a/crypto/src/math/ec/rfc7748/X448Field.cs
+++ b/crypto/src/math/ec/rfc7748/X448Field.cs
@@ -1,6 +1,8 @@
 using System;
 using System.Diagnostics;
 
+using Org.BouncyCastle.Math.Raw;
+
 namespace Org.BouncyCastle.Math.EC.Rfc7748
 {
     [CLSCompliantAttribute(false)]
@@ -20,6 +22,16 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             }
         }
 
+        public static void AddOne(uint[] z)
+        {
+            z[0] += 1;
+        }
+
+        public static void AddOne(uint[] z, int zOff)
+        {
+            z[zOff] += 1;
+        }
+
         //public static void Apm(int[] x, int[] y, int[] zp, int[] zm)
         //{
         //    for (int i = 0; i < Size; ++i)
@@ -62,6 +74,16 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             z[8] = z8; z[9] = z9; z[10] = z10; z[11] = z11; z[12] = z12; z[13] = z13; z[14] = z14; z[15] = z15;
         }
 
+        public static void CNegate(int negate, uint[] z)
+        {
+            Debug.Assert(negate >> 1 == 0);
+
+            uint[] t = Create();
+            Sub(t, z, t);
+
+            Nat.CMov(Size, negate, t, 0, z, 0);
+        }
+
         public static void Copy(uint[] x, int xOff, uint[] z, int zOff)
         {
             for (int i = 0; i < Size; ++i)
@@ -166,25 +188,23 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             // z = x^(p-2) = x^(2^448 - 2^224 - 3)
             // (223 1s) (1 0s) (222 1s) (1 0s) (1 1s)
             // Addition chain: [1] 2 3 6 9 18 19 37 74 111 [222] [223]
-            uint[] x2 = Create();    Sqr(x, x2);             Mul(x, x2, x2);
-            uint[] x3 = Create();    Sqr(x2, x3);            Mul(x, x3, x3);
-            uint[] x6 = Create();    Sqr(x3, 3, x6);         Mul(x3, x6, x6);
-            uint[] x9 = Create();    Sqr(x6, 3, x9);         Mul(x3, x9, x9);
-            uint[] x18 = Create();   Sqr(x9, 9, x18);        Mul(x9, x18, x18);
-            uint[] x19 = Create();   Sqr(x18, x19);          Mul(x, x19, x19);
-            uint[] x37 = Create();   Sqr(x19, 18, x37);      Mul(x18, x37, x37);
-            uint[] x74 = Create();   Sqr(x37, 37, x74);      Mul(x37, x74, x74);
-            uint[] x111 = Create();  Sqr(x74, 37, x111);     Mul(x37, x111, x111);
-            uint[] x222 = Create();  Sqr(x111, 111, x222);   Mul(x111, x222, x222);
-            uint[] x223 = Create();  Sqr(x222, x223);        Mul(x, x223, x223);
 
             uint[] t = Create();
-            Sqr(x223, 223, t);
-            Mul(t, x222, t);
+            PowPm3d4(x, t);
             Sqr(t, 2, t);
             Mul(t, x, z);
         }
 
+        public static bool IsZeroVar(uint[] x)
+        {
+            uint d = 0;
+            for (int i = 0; i < Size; ++i)
+            {
+                d |= x[i];
+            }
+            return d == 0U;
+        }
+
         public static void Mul(uint[] x, uint y, uint[] z)
         {
             uint x0 = x[0], x1 = x[1], x2 = x[2], x3 = x[3], x4 = x[4], x5 = x[5], x6 = x[6], x7 = x[7];
@@ -563,6 +583,12 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             z[15] = z15;
         }
 
+        public static void Negate(uint[] x, uint[] z)
+        {
+            uint[] zero = Create();
+            Sub(zero, x, z);
+        }
+
         public static void Normalize(uint[] z)
         {
             //int x = (z[15] >> (28 - 1)) & 1;
@@ -571,6 +597,37 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             Debug.Assert(z[15] >> 28 == 0U);
         }
 
+        public static void One(uint[] z)
+        {
+            z[0] = 1U;
+            for (int i = 1; i < Size; ++i)
+            {
+                z[i] = 0;
+            }
+        }
+
+        private static void PowPm3d4(uint[] x, uint[] z)
+        {
+            // z = x^((p-3)/4) = x^(2^446 - 2^222 - 1)
+            // (223 1s) (1 0s) (222 1s)
+            // Addition chain: 1 2 3 6 9 18 19 37 74 111 [222] [223]
+            uint[] x2 = Create();   Sqr(x, x2);             Mul(x, x2, x2);
+            uint[] x3 = Create();   Sqr(x2, x3);            Mul(x, x3, x3);
+            uint[] x6 = Create();   Sqr(x3, 3, x6);         Mul(x3, x6, x6);
+            uint[] x9 = Create();   Sqr(x6, 3, x9);         Mul(x3, x9, x9);
+            uint[] x18 = Create();  Sqr(x9, 9, x18);        Mul(x9, x18, x18);
+            uint[] x19 = Create();  Sqr(x18, x19);          Mul(x, x19, x19);
+            uint[] x37 = Create();  Sqr(x19, 18, x37);      Mul(x18, x37, x37);
+            uint[] x74 = Create();  Sqr(x37, 37, x74);      Mul(x37, x74, x74);
+            uint[] x111 = Create(); Sqr(x74, 37, x111);     Mul(x37, x111, x111);
+            uint[] x222 = Create(); Sqr(x111, 111, x222);   Mul(x111, x222, x222);
+            uint[] x223 = Create(); Sqr(x222, x223);        Mul(x, x223, x223);
+
+            uint[] t = Create();
+            Sqr(x223, 223, t);
+            Mul(t, x222, z);
+        }
+
         private static void Reduce(uint[] z, int c)
         {
             uint z15 = z[15];
@@ -836,6 +893,38 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             }
         }
 
+        public static bool SqrtRatioVar(uint[] u, uint[] v, uint[] z)
+        {
+            uint[] u3v = Create();
+            uint[] u5v3 = Create();
+
+            Sqr(u, u3v);
+            Mul(u3v, v, u3v);
+            Sqr(u3v, u5v3);
+            Mul(u3v, u, u3v);
+            Mul(u5v3, u, u5v3);
+            Mul(u5v3, v, u5v3);
+
+            uint[] x = Create();
+            PowPm3d4(u5v3, x);
+            Mul(x, u3v, x);
+
+            uint[] t = Create();
+            Sqr(x, t);
+            Mul(t, v, t);
+
+            Sub(u, t, t);
+            Normalize(t);
+
+            if (IsZeroVar(t))
+            {
+                Copy(x, 0, z, 0);
+                return true;
+            }
+
+            return false;
+        }
+
         public static void Sub(uint[] x, uint[] y, uint[] z)
         {
             uint x0 = x[0], x1 = x[1], x2 = x[2], x3 = x[3], x4 = x[4], x5 = x[5], x6 = x[6], x7 = x[7];
@@ -900,5 +989,13 @@ namespace Org.BouncyCastle.Math.EC.Rfc7748
             z[14] = z14;
             z[15] = z15;
         }
+
+        public static void Zero(uint[] z)
+        {
+            for (int i = 0; i < Size; ++i)
+            {
+                z[i] = 0;
+            }
+        }
     }
 }
diff --git a/crypto/src/math/ec/rfc8032/Ed25519.cs b/crypto/src/math/ec/rfc8032/Ed25519.cs
new file mode 100644
index 000000000..ff4587cb2
--- /dev/null
+++ b/crypto/src/math/ec/rfc8032/Ed25519.cs
@@ -0,0 +1,937 @@
+using System;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+
+using Org.BouncyCastle.Crypto.Digests;
+using Org.BouncyCastle.Math.EC.Rfc7748;
+using Org.BouncyCastle.Math.Raw;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Math.EC.Rfc8032
+{
+    public abstract class Ed25519
+    {
+        private const long M28L = 0x0FFFFFFFL;
+        private const long M32L = 0xFFFFFFFFL;
+
+        private const int PointBytes = 32;
+        private const int ScalarUints = 8;
+        private const int ScalarBytes = ScalarUints * 4;
+
+        public static readonly int PublicKeySize = PointBytes;
+        public static readonly int SecretKeySize = 32;
+        public static readonly int SignatureSize = PointBytes + ScalarBytes;
+
+        //private static readonly byte[] Dom2Prefix = Strings.ToByteArray("SigEd25519 no Ed25519 collisions");
+
+        private static readonly uint[] P = { 0xFFFFFFEDU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0x7FFFFFFFU };
+        private static readonly uint[] L = { 0x5CF5D3EDU, 0x5812631AU, 0xA2F79CD6U, 0x14DEF9DEU, 0x00000000U, 0x00000000U, 0x00000000U, 0x10000000U };
+
+        private const int L0 = unchecked((int)0xFCF5D3ED);  // L0:26/--
+        private const int L1 =                0x012631A6;   // L1:24/22
+        private const int L2 =                0x079CD658;   // L2:27/--
+        private const int L3 = unchecked((int)0xFF9DEA2F);  // L3:23/--
+        private const int L4 =                0x000014DF;   // L4:12/11
+
+        private static readonly int[] B_x = { 0x0325D51A, 0x018B5823, 0x007B2C95, 0x0304A92D, 0x00D2598E, 0x01D6DC5C,
+            0x01388C7F, 0x013FEC0A, 0x029E6B72, 0x0042D26D };
+        private static readonly int[] B_y = { 0x02666658, 0x01999999, 0x00666666, 0x03333333, 0x00CCCCCC, 0x02666666,
+            0x01999999, 0x00666666, 0x03333333, 0x00CCCCCC, };
+        private static readonly int[] C_d = { 0x035978A3, 0x02D37284, 0x018AB75E, 0x026A0A0E, 0x0000E014, 0x0379E898,
+            0x01D01E5D, 0x01E738CC, 0x03715B7F, 0x00A406D9 };
+        private static readonly int[] C_d2 = { 0x02B2F159, 0x01A6E509, 0x01156EBD, 0x00D4141D, 0x0001C029, 0x02F3D130,
+            0x03A03CBB, 0x01CE7198, 0x02E2B6FF, 0x00480DB3 };
+        private static readonly int[] C_d4 = { 0x0165E2B2, 0x034DCA13, 0x002ADD7A, 0x01A8283B, 0x00038052, 0x01E7A260,
+            0x03407977, 0x019CE331, 0x01C56DFF, 0x00901B67 };
+
+        private const int WnafWidthBase = 7;
+
+        private const int PrecompBlocks = 8;
+        private const int PrecompTeeth = 4;
+        private const int PrecompSpacing = 8;
+        private const int PrecompPoints = 1 << (PrecompTeeth - 1);
+        private const int PrecompMask = PrecompPoints - 1;
+
+        // TODO[ed25519] Convert to PointPrecomp
+        private static PointExt[] precompBaseTable = null;
+        private static int[] precompBase = null;
+
+        private class PointAccum
+        {
+            internal int[] x = X25519Field.Create();
+            internal int[] y = X25519Field.Create();
+            internal int[] z = X25519Field.Create();
+            internal int[] u = X25519Field.Create();
+            internal int[] v = X25519Field.Create();
+        }
+
+        private class PointExt
+        {
+            internal int[] x = X25519Field.Create();
+            internal int[] y = X25519Field.Create();
+            internal int[] z = X25519Field.Create();
+            internal int[] t = X25519Field.Create();
+        }
+
+        private class PointPrecomp
+        {
+            internal int[] ypx_h = X25519Field.Create();
+            internal int[] ymx_h = X25519Field.Create();
+            internal int[] xyd = X25519Field.Create();
+        }
+
+        private static byte[] CalculateS(byte[] r, byte[] k, byte[] s)
+        {
+            uint[] t = new uint[ScalarUints * 2];   DecodeScalar(r, 0, t);
+            uint[] u = new uint[ScalarUints];       DecodeScalar(k, 0, u);
+            uint[] v = new uint[ScalarUints];       DecodeScalar(s, 0, v);
+
+            Nat256.MulAddTo(u, v, t);
+
+            byte[] result = new byte[ScalarBytes * 2];
+            for (int i = 0; i < t.Length; ++i)
+            {
+                Encode32(t[i], result, i * 4);
+            }
+            return ReduceScalar(result);
+        }
+
+        private static bool CheckPointVar(byte[] p)
+        {
+            uint[] t = new uint[8];
+            Decode32(p, 0, t, 0, 8);
+            t[7] &= 0x7FFFFFFFU;
+            return !Nat256.Gte(t, P);
+        }
+
+        private static bool CheckScalarVar(byte[] s)
+        {
+            uint[] n = new uint[ScalarUints];
+            DecodeScalar(s, 0, n);
+            return !Nat256.Gte(n, L);
+        }
+
+        private static uint Decode24(byte[] bs, int off)
+        {
+            uint n = bs[off];
+            n |= (uint)bs[++off] << 8;
+            n |= (uint)bs[++off] << 16;
+            return n;
+        }
+
+        private static uint Decode32(byte[] bs, int off)
+        {
+            uint n = bs[off];
+            n |= (uint)bs[++off] << 8;
+            n |= (uint)bs[++off] << 16;
+            n |= (uint)bs[++off] << 24;
+            return n;
+        }
+
+        private static void Decode32(byte[] bs, int bsOff, uint[] n, int nOff, int nLen)
+        {
+            for (int i = 0; i < nLen; ++i)
+            {
+                n[nOff + i] = Decode32(bs, bsOff + i * 4);
+            }
+        }
+
+        private static bool DecodePointVar(byte[] p, int pOff, bool negate, PointExt r)
+        {
+            byte[] py = Arrays.CopyOfRange(p, pOff, pOff + PointBytes);
+            if (!CheckPointVar(py))
+            {
+                return false;
+            }
+
+            int x_0 = (py[PointBytes - 1] & 0x80) >> 7;
+            py[PointBytes - 1] &= 0x7F;
+
+            X25519Field.Decode(py, 0, r.y);
+
+            int[] u = X25519Field.Create();
+            int[] v = X25519Field.Create();
+
+            X25519Field.Sqr(r.y, u);
+            X25519Field.Mul(C_d, u, v);
+            X25519Field.SubOne(u);
+            X25519Field.AddOne(v);
+
+            if (!X25519Field.SqrtRatioVar(u, v, r.x))
+            {
+                return false;
+            }
+
+            X25519Field.Normalize(r.x);
+            if (x_0 == 1 && X25519Field.IsZeroVar(r.x))
+            {
+                return false;
+            }
+
+            if (negate ^ (x_0 != (r.x[0] & 1)))
+            {
+                X25519Field.Negate(r.x, r.x);
+            }
+
+            PointExtendXY(r);
+            return true;
+        }
+
+        private static void DecodeScalar(byte[] k, int kOff, uint[] n)
+        {
+            Decode32(k, kOff, n, 0, ScalarUints);
+        }
+
+        private static void Encode24(uint n, byte[] bs, int off)
+        {
+            bs[off] = (byte)(n);
+            bs[++off] = (byte)(n >> 8);
+            bs[++off] = (byte)(n >> 16);
+        }
+
+        private static void Encode32(uint n, byte[] bs, int off)
+        {
+            bs[off] = (byte)(n);
+            bs[++off] = (byte)(n >> 8);
+            bs[++off] = (byte)(n >> 16);
+            bs[++off] = (byte)(n >> 24);
+        }
+
+        private static void Encode56(ulong n, byte[] bs, int off)
+        {
+            Encode32((uint)n, bs, off);
+            Encode24((uint)(n >> 32), bs, off + 4);
+        }
+
+        private static void EncodePoint(PointAccum p, byte[] r, int rOff)
+        {
+            int[] x = X25519Field.Create();
+            int[] y = X25519Field.Create();
+
+            X25519Field.Inv(p.z, y);
+            X25519Field.Mul(p.x, y, x);
+            X25519Field.Mul(p.y, y, y);
+            X25519Field.Normalize(x);
+            X25519Field.Normalize(y);
+
+            X25519Field.Encode(y, r, rOff);
+            r[rOff + PointBytes - 1] |= (byte)((x[0] & 1) << 7);
+        }
+
+        public static void GeneratePublicKey(byte[] sk, int skOff, byte[] pk, int pkOff)
+        {
+            Sha512Digest d = new Sha512Digest();
+            byte[] h = new byte[d.GetDigestSize()];
+
+            d.BlockUpdate(sk, skOff, SecretKeySize);
+            d.DoFinal(h, 0);
+
+            byte[] s = new byte[ScalarBytes];
+            PruneScalar(h, 0, s);
+
+            ScalarMultBaseEncoded(s, pk, pkOff);
+        }
+
+        private static sbyte[] GetWnaf(uint[] n, int width)
+        {
+            Debug.Assert(n[ScalarUints - 1] >> 31 == 0);
+
+            uint[] t = new uint[ScalarUints * 2];
+            {
+                uint c = 0;
+                int tPos = t.Length, i = ScalarUints;
+                while (--i >= 0)
+                {
+                    uint next = n[i];
+                    t[--tPos] = (next >> 16) | (c << 16);
+                    t[--tPos] = c = next;
+                }
+            }
+
+            sbyte[] ws = new sbyte[256];
+
+            uint pow2 = 1U << width;
+            uint mask = pow2 - 1U;
+            uint sign = pow2 >> 1;
+
+            uint carry = 0U;
+            int j = 0;
+            for (int i = 0; i < t.Length; ++i, j -= 16)
+            {
+                uint word = t[i];
+                while (j < 16)
+                {
+                    uint word16 = word >> j;
+                    uint bit = word16 & 1U;
+
+                    if (bit == carry)
+                    {
+                        ++j;
+                        continue;
+                    }
+
+                    uint digit = (word16 & mask) + carry;
+                    carry = digit & sign;
+                    digit -= (carry << 1);
+                    carry >>= (width - 1);
+
+                    ws[(i << 4) + j] = (sbyte)digit;
+
+                    j += width;
+                }
+            }
+
+            Debug.Assert(carry == 0);
+
+            return ws;
+        }
+
+        private static void ImplSign(Sha512Digest d, byte[] h, byte[] s, byte[] pk, int pkOff, byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
+        {
+            d.BlockUpdate(h, ScalarBytes, ScalarBytes);
+            d.BlockUpdate(m, mOff, mLen);
+            d.DoFinal(h, 0);
+
+            byte[] r = ReduceScalar(h);
+            byte[] R = new byte[PointBytes];
+            ScalarMultBaseEncoded(r, R, 0);
+
+            d.BlockUpdate(R, 0, PointBytes);
+            d.BlockUpdate(pk, 0, PointBytes);
+            d.BlockUpdate(m, mOff, mLen);
+            d.DoFinal(h, 0);
+
+            byte[] k = ReduceScalar(h);
+            byte[] S = CalculateS(r, k, s);
+
+            Array.Copy(R, 0, sig, sigOff, PointBytes);
+            Array.Copy(S, 0, sig, sigOff + PointBytes, ScalarBytes);
+        }
+
+        private static void PointAddVar(bool negate, PointExt p, PointAccum r)
+        {
+            int[] A = X25519Field.Create();
+            int[] B = X25519Field.Create();
+            int[] C = X25519Field.Create();
+            int[] D = X25519Field.Create();
+            int[] E = r.u;
+            int[] F = X25519Field.Create();
+            int[] G = X25519Field.Create();
+            int[] H = r.v;
+
+            int[] c, d, f, g;
+            if (negate)
+            {
+                c = D; d = C; f = G; g = F;
+            }
+            else
+            {
+                c = C; d = D; f = F; g = G;
+            }
+
+            X25519Field.Apm(r.y, r.x, B, A);
+            X25519Field.Apm(p.y, p.x, d, c);
+            X25519Field.Mul(A, C, A);
+            X25519Field.Mul(B, D, B);
+            X25519Field.Mul(r.u, r.v, C);
+            X25519Field.Mul(C, p.t, C);
+            X25519Field.Mul(C, C_d2, C);
+            X25519Field.Mul(r.z, p.z, D);
+            X25519Field.Add(D, D, D);
+            X25519Field.Apm(B, A, H, E);
+            X25519Field.Apm(D, C, g, f);
+            X25519Field.Carry(g);
+            X25519Field.Mul(E, F, r.x);
+            X25519Field.Mul(G, H, r.y);
+            X25519Field.Mul(F, G, r.z);
+        }
+
+        private static void PointAddVar(bool negate, PointExt p, PointExt q, PointExt r)
+        {
+            int[] A = X25519Field.Create();
+            int[] B = X25519Field.Create();
+            int[] C = X25519Field.Create();
+            int[] D = X25519Field.Create();
+            int[] E = X25519Field.Create();
+            int[] F = X25519Field.Create();
+            int[] G = X25519Field.Create();
+            int[] H = X25519Field.Create();
+
+            int[] c, d, f, g;
+            if (negate)
+            {
+                c = D; d = C; f = G; g = F;
+            }
+            else
+            {
+                c = C; d = D; f = F; g = G;
+            }
+
+            X25519Field.Apm(p.y, p.x, B, A);
+            X25519Field.Apm(q.y, q.x, d, c);
+            X25519Field.Mul(A, C, A);
+            X25519Field.Mul(B, D, B);
+            X25519Field.Mul(p.t, q.t, C);
+            X25519Field.Mul(C, C_d2, C);
+            X25519Field.Mul(p.z, q.z, D);
+            X25519Field.Add(D, D, D);
+            X25519Field.Apm(B, A, H, E);
+            X25519Field.Apm(D, C, g, f);
+            X25519Field.Carry(g);
+            X25519Field.Mul(E, F, r.x);
+            X25519Field.Mul(G, H, r.y);
+            X25519Field.Mul(F, G, r.z);
+            X25519Field.Mul(E, H, r.t);
+        }
+
+        private static void PointAddPrecomp(PointPrecomp p, PointAccum r)
+        {
+            int[] A = X25519Field.Create();
+            int[] B = X25519Field.Create();
+            int[] C = X25519Field.Create();
+            int[] E = r.u;
+            int[] F = X25519Field.Create();
+            int[] G = X25519Field.Create();
+            int[] H = r.v;
+
+            X25519Field.Apm(r.y, r.x, B, A);
+            X25519Field.Mul(A, p.ymx_h, A);
+            X25519Field.Mul(B, p.ypx_h, B);
+            X25519Field.Mul(r.u, r.v, C);
+            X25519Field.Mul(C, p.xyd, C);
+            X25519Field.Apm(B, A, H, E);
+            X25519Field.Apm(r.z, C, G, F);
+            X25519Field.Carry(G);
+            X25519Field.Mul(E, F, r.x);
+            X25519Field.Mul(G, H, r.y);
+            X25519Field.Mul(F, G, r.z);
+        }
+
+        private static PointExt PointCopy(PointAccum p)
+        {
+            PointExt r = new PointExt();
+            X25519Field.Copy(p.x, 0, r.x, 0);
+            X25519Field.Copy(p.y, 0, r.y, 0);
+            X25519Field.Copy(p.z, 0, r.z, 0);
+            X25519Field.Mul(p.u, p.v, r.t);
+            return r;
+        }
+
+        private static PointExt PointCopy(PointExt p)
+        {
+            PointExt r = new PointExt();
+            X25519Field.Copy(p.x, 0, r.x, 0);
+            X25519Field.Copy(p.y, 0, r.y, 0);
+            X25519Field.Copy(p.z, 0, r.z, 0);
+            X25519Field.Copy(p.t, 0, r.t, 0);
+            return r;
+        }
+
+        private static void PointDouble(PointAccum r)
+        {
+            int[] A = X25519Field.Create();
+            int[] B = X25519Field.Create();
+            int[] C = X25519Field.Create();
+            int[] E = r.u;
+            int[] F = X25519Field.Create();
+            int[] G = X25519Field.Create();
+            int[] H = r.v;
+
+            X25519Field.Sqr(r.x, A);
+            X25519Field.Sqr(r.y, B);
+            X25519Field.Sqr(r.z, C);
+            X25519Field.Add(C, C, C);
+            X25519Field.Apm(A, B, H, G);
+            X25519Field.Add(r.x, r.y, E);
+            X25519Field.Sqr(E, E);
+            X25519Field.Sub(H, E, E);
+            X25519Field.Add(C, G, F);
+            X25519Field.Carry(F);
+            X25519Field.Mul(E, F, r.x);
+            X25519Field.Mul(G, H, r.y);
+            X25519Field.Mul(F, G, r.z);
+        }
+
+        private static void PointExtendXY(PointAccum p)
+        {
+            X25519Field.One(p.z);
+            X25519Field.Copy(p.x, 0, p.u, 0);
+            X25519Field.Copy(p.y, 0, p.v, 0);
+        }
+
+        private static void PointExtendXY(PointExt p)
+        {
+            X25519Field.One(p.z);
+            X25519Field.Mul(p.x, p.y, p.t);
+        }
+
+        private static void PointLookup(int block, int index, PointPrecomp p)
+        {
+            Debug.Assert(0 <= block && block < PrecompBlocks);
+            Debug.Assert(0 <= index && index < PrecompPoints);
+
+            int off = block * PrecompPoints * 3 * X25519Field.Size;
+
+            for (int i = 0; i < PrecompPoints; ++i)
+            {
+                int mask = ((i ^ index) - 1) >> 31;
+                Nat.CMov(X25519Field.Size, mask, precompBase, off, p.ypx_h, 0); off += X25519Field.Size;
+                Nat.CMov(X25519Field.Size, mask, precompBase, off, p.ymx_h, 0); off += X25519Field.Size;
+                Nat.CMov(X25519Field.Size, mask, precompBase, off, p.xyd, 0);   off += X25519Field.Size;
+            }
+        }
+
+        private static PointExt[] PointPrecompVar(PointExt p, int count)
+        {
+            Debug.Assert(count > 0);
+
+            PointExt d = new PointExt();
+            PointAddVar(false, p, p, d);
+
+            PointExt[] table = new PointExt[count];
+            table[0] = PointCopy(p);
+            for (int i = 1; i < count; ++i)
+            {
+                PointAddVar(false, table[i - 1], d, table[i] = new PointExt());
+            }
+            return table;
+        }
+
+        private static void PointSetNeutral(PointAccum p)
+        {
+            X25519Field.Zero(p.x);
+            X25519Field.One(p.y);
+            X25519Field.One(p.z);
+            X25519Field.Zero(p.u);
+            X25519Field.One(p.v);
+        }
+
+        private static void PointSetNeutral(PointExt p)
+        {
+            X25519Field.Zero(p.x);
+            X25519Field.One(p.y);
+            X25519Field.One(p.z);
+            X25519Field.Zero(p.t);
+        }
+
+        [MethodImpl(MethodImplOptions.Synchronized)]
+        public static void Precompute()
+        {
+            if (precompBase != null)
+            {
+                return;
+            }
+
+            // Precomputed table for the base point in verification ladder
+            {
+                PointExt b = new PointExt();
+                X25519Field.Copy(B_x, 0, b.x, 0);
+                X25519Field.Copy(B_y, 0, b.y, 0);
+                PointExtendXY(b);
+
+                precompBaseTable = PointPrecompVar(b, 1 << (WnafWidthBase - 2));
+            }
+
+            PointAccum p = new PointAccum();
+            X25519Field.Copy(B_x, 0, p.x, 0);
+            X25519Field.Copy(B_y, 0, p.y, 0);
+            PointExtendXY(p);
+
+            precompBase = new int[PrecompBlocks * PrecompPoints * 3 * X25519Field.Size];
+
+            int off = 0;
+            for (int b = 0; b < PrecompBlocks; ++b)
+            {
+                PointExt[] ds = new PointExt[PrecompTeeth];
+
+                PointExt sum = new PointExt();
+                PointSetNeutral(sum);
+
+                for (int t = 0; t < PrecompTeeth; ++t)
+                {
+                    PointExt q = PointCopy(p);
+                    PointAddVar(true, sum, q, sum);
+                    PointDouble(p);
+
+                    ds[t] = PointCopy(p);
+
+                    for (int s = 1; s < PrecompSpacing; ++s)
+                    {
+                        PointDouble(p);
+                    }
+                }
+
+                PointExt[] points = new PointExt[PrecompPoints];
+                int k = 0;
+                points[k++] = sum;
+
+                for (int t = 0; t < (PrecompTeeth - 1); ++t)
+                {
+                    int size = 1 << t;
+                    for (int j = 0; j < size; ++j, ++k)
+                    {
+                        PointAddVar(false, points[k - size], ds[t], points[k] = new PointExt());
+                    }
+                }
+
+                Debug.Assert(k == PrecompPoints);
+
+                for (int i = 0; i < PrecompPoints; ++i)
+                {
+                    PointExt q = points[i];
+
+                    int[] x = X25519Field.Create();
+                    int[] y = X25519Field.Create();
+
+                    X25519Field.Add(q.z, q.z, x);
+                    // TODO[ed25519] Batch inversion
+                    X25519Field.Inv(x, y);
+                    X25519Field.Mul(q.x, y, x);
+                    X25519Field.Mul(q.y, y, y);
+
+                    PointPrecomp r = new PointPrecomp();
+                    X25519Field.Apm(y, x, r.ypx_h, r.ymx_h);
+                    X25519Field.Mul(x, y, r.xyd);
+                    X25519Field.Mul(r.xyd, C_d4, r.xyd);
+
+                    X25519Field.Normalize(r.ypx_h);
+                    X25519Field.Normalize(r.ymx_h);
+                    //X25519Field.Normalize(r.xyd);
+
+                    X25519Field.Copy(r.ypx_h, 0, precompBase, off); off += X25519Field.Size;
+                    X25519Field.Copy(r.ymx_h, 0, precompBase, off); off += X25519Field.Size;
+                    X25519Field.Copy(r.xyd, 0, precompBase, off);   off += X25519Field.Size;
+                }
+            }
+
+            Debug.Assert(off == precompBase.Length);
+        }
+
+        private static void PruneScalar(byte[] n, int nOff, byte[] r)
+        {
+            Array.Copy(n, nOff, r, 0, ScalarBytes);
+
+            r[0] &= 0xF8;
+            r[ScalarBytes - 1] &= 0x7F;
+            r[ScalarBytes - 1] |= 0x40;
+        }
+
+        private static byte[] ReduceScalar(byte[] n)
+        {
+            long x00 = Decode32(n,  0) & M32L;          // x00:32/--
+            long x01 = (Decode24(n, 4) << 4) & M32L;    // x01:28/--
+            long x02 = Decode32(n,  7) & M32L;          // x02:32/--
+            long x03 = (Decode24(n, 11) << 4) & M32L;   // x03:28/--
+            long x04 = Decode32(n, 14) & M32L;          // x04:32/--
+            long x05 = (Decode24(n, 18) << 4) & M32L;   // x05:28/--
+            long x06 = Decode32(n, 21) & M32L;          // x06:32/--
+            long x07 = (Decode24(n, 25) << 4) & M32L;   // x07:28/--
+            long x08 = Decode32(n, 28) & M32L;          // x08:32/--
+            long x09 = (Decode24(n, 32) << 4) & M32L;   // x09:28/--
+            long x10 = Decode32(n, 35) & M32L;          // x10:32/--
+            long x11 = (Decode24(n, 39) << 4) & M32L;   // x11:28/--
+            long x12 = Decode32(n, 42) & M32L;          // x12:32/--
+            long x13 = (Decode24(n, 46) << 4) & M32L;   // x13:28/--
+            long x14 = Decode32(n, 49) & M32L;          // x14:32/--
+            long x15 = (Decode24(n, 53) << 4) & M32L;   // x15:28/--
+            long x16 = Decode32(n, 56) & M32L;          // x16:32/--
+            long x17 = (Decode24(n, 60) << 4) & M32L;   // x17:28/--
+            long x18 = n[63] & 0xFFL;                   // x18:08/--
+            long t;
+
+            //x18 += (x17 >> 28); x17 &= M28L;
+            x09 -= x18 * L0;                            // x09:34/28
+            x10 -= x18 * L1;                            // x10:33/30
+            x11 -= x18 * L2;                            // x11:35/28
+            x12 -= x18 * L3;                            // x12:32/31
+            x13 -= x18 * L4;                            // x13:28/21
+
+            x17 += (x16 >> 28); x16 &= M28L;            // x17:28/--, x16:28/--
+            x08 -= x17 * L0;                            // x08:54/32
+            x09 -= x17 * L1;                            // x09:52/51
+            x10 -= x17 * L2;                            // x10:55/34
+            x11 -= x17 * L3;                            // x11:51/36
+            x12 -= x17 * L4;                            // x12:41/--
+
+            //x16 += (x15 >> 28); x15 &= M28L;
+            x07 -= x16 * L0;                            // x07:54/28
+            x08 -= x16 * L1;                            // x08:54/53
+            x09 -= x16 * L2;                            // x09:55/53
+            x10 -= x16 * L3;                            // x10:55/52
+            x11 -= x16 * L4;                            // x11:51/41
+
+            x15 += (x14 >> 28); x14 &= M28L;            // x15:28/--, x14:28/--
+            x06 -= x15 * L0;                            // x06:54/32
+            x07 -= x15 * L1;                            // x07:54/53
+            x08 -= x15 * L2;                            // x08:56/--
+            x09 -= x15 * L3;                            // x09:55/54
+            x10 -= x15 * L4;                            // x10:55/53
+
+            //x14 += (x13 >> 28); x13 &= M28L;
+            x05 -= x14 * L0;                            // x05:54/28
+            x06 -= x14 * L1;                            // x06:54/53
+            x07 -= x14 * L2;                            // x07:56/--
+            x08 -= x14 * L3;                            // x08:56/51
+            x09 -= x14 * L4;                            // x09:56/--
+
+            x13 += (x12 >> 28); x12 &= M28L;            // x13:28/22, x12:28/--
+            x04 -= x13 * L0;                            // x04:54/49
+            x05 -= x13 * L1;                            // x05:54/53
+            x06 -= x13 * L2;                            // x06:56/--
+            x07 -= x13 * L3;                            // x07:56/52
+            x08 -= x13 * L4;                            // x08:56/52
+
+            x12 += (x11 >> 28); x11 &= M28L;            // x12:28/24, x11:28/--
+            x03 -= x12 * L0;                            // x03:54/49
+            x04 -= x12 * L1;                            // x04:54/51
+            x05 -= x12 * L2;                            // x05:56/--
+            x06 -= x12 * L3;                            // x06:56/52
+            x07 -= x12 * L4;                            // x07:56/53
+
+            x11 += (x10 >> 28); x10 &= M28L;            // x11:29/--, x10:28/--
+            x02 -= x11 * L0;                            // x02:55/32
+            x03 -= x11 * L1;                            // x03:55/--
+            x04 -= x11 * L2;                            // x04:56/55
+            x05 -= x11 * L3;                            // x05:56/52
+            x06 -= x11 * L4;                            // x06:56/53
+
+            x10 += (x09 >> 28); x09 &= M28L;            // x10:29/--, x09:28/--
+            x01 -= x10 * L0;                            // x01:55/28
+            x02 -= x10 * L1;                            // x02:55/54
+            x03 -= x10 * L2;                            // x03:56/55
+            x04 -= x10 * L3;                            // x04:57/--
+            x05 -= x10 * L4;                            // x05:56/53
+
+            x08 += (x07 >> 28); x07 &= M28L;            // x08:56/53, x07:28/--
+            x09 += (x08 >> 28); x08 &= M28L;            // x09:29/25, x08:28/--
+
+            t    = (x08 >> 27) & 1L;
+            x09 += t;                                   // x09:29/26
+
+            x00 -= x09 * L0;                            // x00:55/53
+            x01 -= x09 * L1;                            // x01:55/54
+            x02 -= x09 * L2;                            // x02:57/--
+            x03 -= x09 * L3;                            // x03:57/--
+            x04 -= x09 * L4;                            // x04:57/42
+
+            x01 += (x00 >> 28); x00 &= M28L;
+            x02 += (x01 >> 28); x01 &= M28L;
+            x03 += (x02 >> 28); x02 &= M28L;
+            x04 += (x03 >> 28); x03 &= M28L;
+            x05 += (x04 >> 28); x04 &= M28L;
+            x06 += (x05 >> 28); x05 &= M28L;
+            x07 += (x06 >> 28); x06 &= M28L;
+            x08 += (x07 >> 28); x07 &= M28L;
+            x09  = (x08 >> 28); x08 &= M28L;
+
+            x09 -= t;
+
+            Debug.Assert(x09 == 0L || x09 == -1L);
+
+            x00 += x09 & L0;
+            x01 += x09 & L1;
+            x02 += x09 & L2;
+            x03 += x09 & L3;
+            x04 += x09 & L4;
+
+            x01 += (x00 >> 28); x00 &= M28L;
+            x02 += (x01 >> 28); x01 &= M28L;
+            x03 += (x02 >> 28); x02 &= M28L;
+            x04 += (x03 >> 28); x03 &= M28L;
+            x05 += (x04 >> 28); x04 &= M28L;
+            x06 += (x05 >> 28); x05 &= M28L;
+            x07 += (x06 >> 28); x06 &= M28L;
+            x08 += (x07 >> 28); x07 &= M28L;
+
+            byte[] r = new byte[ScalarBytes];
+            Encode56((ulong)(x00 | (x01 << 28)), r, 0);
+            Encode56((ulong)(x02 | (x03 << 28)), r, 7);
+            Encode56((ulong)(x04 | (x05 << 28)), r, 14);
+            Encode56((ulong)(x06 | (x07 << 28)), r, 21);
+            Encode32((uint)x08, r, 28);
+            return r;
+        }
+
+        private static void ScalarMultBase(byte[] k, PointAccum r)
+        {
+            Precompute();
+
+            PointSetNeutral(r);
+
+            uint[] n = new uint[ScalarUints];
+            DecodeScalar(k, 0, n);
+
+            // Recode the scalar into signed-digit form, then group comb bits in each block
+            {
+                uint c1 = Nat.CAdd(ScalarUints, ~(int)n[0] & 1, n, L, n);   Debug.Assert(c1 == 0);
+                uint c2 = Nat.ShiftDownBit(ScalarUints, n, 1U);             Debug.Assert(c2 == (1U << 31));
+
+                for (int i = 0; i < ScalarUints; ++i)
+                {
+                    n[i] = Interleave.Shuffle2(n[i]);
+                }
+            }
+
+            PointPrecomp p = new PointPrecomp();
+
+            int cOff = (PrecompSpacing - 1) * PrecompTeeth;
+            for (; ; )
+            {
+                for (int b = 0; b < PrecompBlocks; ++b)
+                {
+                    uint w = n[b] >> cOff;
+                    int sign = (int)(w >> (PrecompTeeth - 1)) & 1;
+                    int abs = ((int)w ^ -sign) & PrecompMask;
+
+                    Debug.Assert(sign == 0 || sign == 1);
+                    Debug.Assert(0 <= abs && abs < PrecompPoints);
+
+                    PointLookup(b, abs, p);
+
+                    X25519Field.CSwap(sign, p.ypx_h, p.ymx_h);
+                    X25519Field.CNegate(sign, p.xyd);
+
+                    PointAddPrecomp(p, r);
+                }
+
+                if ((cOff -= PrecompTeeth) < 0)
+                {
+                    break;
+                }
+
+                PointDouble(r);
+            }
+        }
+
+        private static void ScalarMultBaseEncoded(byte[] k, byte[] r, int rOff)
+        {
+            PointAccum p = new PointAccum();
+            ScalarMultBase(k, p);
+            EncodePoint(p, r, rOff);
+        }
+
+        private static void ScalarMultStraussVar(uint[] nb, uint[] np, PointExt p, PointAccum r)
+        {
+            Precompute();
+
+            int width = 5;
+
+            sbyte[] ws_b = GetWnaf(nb, WnafWidthBase);
+            sbyte[] ws_p = GetWnaf(np, width);
+
+            PointExt[] tp = PointPrecompVar(p, 1 << (width - 2));
+
+            PointSetNeutral(r);
+
+            int bit = 255;
+            while (bit > 0 && (ws_b[bit] | ws_p[bit]) == 0)
+            {
+                --bit;
+            }
+
+            for (; ; )
+            {
+                int wb = ws_b[bit];
+                if (wb != 0)
+                {
+                    int sign = wb >> 31;
+                    int index = (wb ^ sign) >> 1;
+
+                    PointAddVar((sign != 0), precompBaseTable[index], r);
+                }
+
+                int wp = ws_p[bit];
+                if (wp != 0)
+                {
+                    int sign = wp >> 31;
+                    int index = (wp ^ sign) >> 1;
+
+                    PointAddVar((sign != 0), tp[index], r);
+                }
+
+                if (--bit < 0)
+                {
+                    break;
+                }
+
+                PointDouble(r);
+            }
+        }
+
+        public static void Sign(byte[] sk, int skOff, byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
+        {
+            Sha512Digest d = new Sha512Digest();
+            byte[] h = new byte[d.GetDigestSize()];
+
+            d.BlockUpdate(sk, skOff, SecretKeySize);
+            d.DoFinal(h, 0);
+
+            byte[] s = new byte[ScalarBytes];
+            PruneScalar(h, 0, s);
+
+            byte[] pk = new byte[PointBytes];
+            ScalarMultBaseEncoded(s, pk, 0);
+
+            ImplSign(d, h, s, pk, 0, m, mOff, mLen, sig, sigOff);
+        }
+
+        public static void Sign(byte[] sk, int skOff, byte[] pk, int pkOff, byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
+        {
+            Sha512Digest d = new Sha512Digest();
+            byte[] h = new byte[d.GetDigestSize()];
+
+            d.BlockUpdate(sk, skOff, SecretKeySize);
+            d.DoFinal(h, 0);
+
+            byte[] s = new byte[ScalarBytes];
+            PruneScalar(h, 0, s);
+
+            ImplSign(d, h, s, pk, pkOff, m, mOff, mLen, sig, sigOff);
+        }
+
+        public static bool Verify(byte[] sig, int sigOff, byte[] pk, int pkOff, byte[] m, int mOff, int mLen)
+        {
+            byte[] R = Arrays.CopyOfRange(sig, sigOff, sigOff + PointBytes);
+            byte[] S = Arrays.CopyOfRange(sig, sigOff + PointBytes, sigOff + SignatureSize);
+
+            if (!CheckPointVar(R))
+            {
+                return false;
+            }
+            if (!CheckScalarVar(S))
+            {
+                return false;
+            }
+
+            PointExt pA = new PointExt();
+            if (!DecodePointVar(pk, pkOff, true, pA))
+            {
+                return false;
+            }
+
+            Sha512Digest d = new Sha512Digest();
+            byte[] h = new byte[d.GetDigestSize()];
+
+            d.BlockUpdate(R, 0, PointBytes);
+            d.BlockUpdate(pk, pkOff, PointBytes);
+            d.BlockUpdate(m, mOff, mLen);
+            d.DoFinal(h, 0);
+
+            byte[] k = ReduceScalar(h);
+
+            uint[] nS = new uint[ScalarUints];
+            DecodeScalar(S, 0, nS);
+
+            uint[] nA = new uint[ScalarUints];
+            DecodeScalar(k, 0, nA);
+
+            PointAccum pR = new PointAccum();
+            ScalarMultStraussVar(nS, nA, pA, pR);
+
+            byte[] check = new byte[PointBytes];
+            EncodePoint(pR, check, 0);
+
+            return Arrays.AreEqual(check, R);
+        }
+    }
+}
diff --git a/crypto/src/math/ec/rfc8032/Ed448.cs b/crypto/src/math/ec/rfc8032/Ed448.cs
new file mode 100644
index 000000000..52c215160
--- /dev/null
+++ b/crypto/src/math/ec/rfc8032/Ed448.cs
@@ -0,0 +1,1067 @@
+using System;
+using System.Diagnostics;
+using System.Runtime.CompilerServices;
+
+using Org.BouncyCastle.Crypto.Digests;
+using Org.BouncyCastle.Math.EC.Rfc7748;
+using Org.BouncyCastle.Math.Raw;
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Math.EC.Rfc8032
+{
+    public abstract class Ed448
+    {
+        private const ulong M26UL = 0x03FFFFFFUL;
+        private const ulong M28UL = 0x0FFFFFFFUL;
+
+        private const int PointBytes = 57;
+        private const int ScalarUints = 14;
+        private const int ScalarBytes = ScalarUints * 4 + 1;
+
+        public static readonly int PublicKeySize = PointBytes;
+        public static readonly int SecretKeySize = 57;
+        public static readonly int SignatureSize = PointBytes + ScalarBytes;
+
+        private static readonly byte[] Dom4Prefix = Strings.ToByteArray("SigEd448");
+
+        private static readonly uint[] P = { 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU,
+            0xFFFFFFFEU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU };
+        private static readonly uint[] L = { 0xAB5844F3U, 0x2378C292U, 0x8DC58F55U, 0x216CC272U, 0xAED63690U, 0xC44EDB49U, 0x7CCA23E9U,
+            0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0xFFFFFFFFU, 0x3FFFFFFFU };
+        private static readonly BigInteger N = Nat.ToBigInteger(L.Length, L);
+
+        private const int L_0 = 0x04A7BB0D;     // L_0:26/24
+        private const int L_1 = 0x0873D6D5;     // L_1:27/23
+        private const int L_2 = 0x0A70AADC;     // L_2:27/26
+        private const int L_3 = 0x03D8D723;     // L_3:26/--
+        private const int L_4 = 0x096FDE93;     // L_4:27/25
+        private const int L_5 = 0x0B65129C;     // L_5:27/26
+        private const int L_6 = 0x063BB124;     // L_6:27/--
+        private const int L_7 = 0x08335DC1;     // L_7:27/22
+
+        private const int L4_0 = 0x029EEC34;    // L4_0:25/24
+        private const int L4_1 = 0x01CF5B55;    // L4_1:25/--
+        private const int L4_2 = 0x09C2AB72;    // L4_2:27/25
+        private const int L4_3 = 0x0F635C8E;    // L4_3:28/--
+        private const int L4_4 = 0x05BF7A4C;    // L4_4:26/25
+        private const int L4_5 = 0x0D944A72;    // L4_5:28/--
+        private const int L4_6 = 0x08EEC492;    // L4_6:27/24
+        private const int L4_7 = 0x20CD7705;    // L4_7:29/24
+
+        private static readonly uint[] B_x = { 0x070CC05EU, 0x026A82BCU, 0x00938E26U, 0x080E18B0U, 0x0511433BU, 0x0F72AB66U, 0x0412AE1AU,
+            0x0A3D3A46U, 0x0A6DE324U, 0x00F1767EU, 0x04657047U, 0x036DA9E1U, 0x05A622BFU, 0x0ED221D1U, 0x066BED0DU, 0x04F1970CU };
+        private static readonly uint[] B_y = { 0x0230FA14U, 0x008795BFU, 0x07C8AD98U, 0x0132C4EDU, 0x09C4FDBDU, 0x01CE67C3U, 0x073AD3FFU,
+            0x005A0C2DU, 0x07789C1EU, 0x0A398408U, 0x0A73736CU, 0x0C7624BEU, 0x003756C9U, 0x02488762U, 0x016EB6BCU, 0x0693F467U };
+        private const int C_d = -39081;
+
+        private const int WnafWidthBase = 7;
+
+        private const int PrecompBlocks = 5;
+        private const int PrecompTeeth = 5;
+        private const int PrecompSpacing = 18;
+        private const int PrecompPoints = 1 << (PrecompTeeth - 1);
+        private const int PrecompMask = PrecompPoints - 1;
+
+        // TODO[ed448] Convert to PointPrecomp
+        private static PointExt[] precompBaseTable = null;
+        private static uint[] precompBase = null;
+
+        private class PointExt
+        {
+            internal uint[] x = X448Field.Create();
+            internal uint[] y = X448Field.Create();
+            internal uint[] z = X448Field.Create();
+        }
+
+        private class PointPrecomp
+        {
+            internal uint[] x = X448Field.Create();
+            internal uint[] y = X448Field.Create();
+        }
+
+        private static byte[] CalculateS(byte[] r, byte[] k, byte[] s)
+        {
+            uint[] t = new uint[ScalarUints * 2];   DecodeScalar(r, 0, t);
+            uint[] u = new uint[ScalarUints];       DecodeScalar(k, 0, u);
+            uint[] v = new uint[ScalarUints];       DecodeScalar(s, 0, v);
+
+            Nat.MulAddTo(14, u, v, t);
+
+            byte[] result = new byte[ScalarBytes * 2];
+            for (int i = 0; i < t.Length; ++i)
+            {
+                Encode32(t[i], result, i * 4);
+            }
+            return ReduceScalar(result);
+        }
+
+        private static bool CheckContextVar(byte[] ctx)
+        {
+            return ctx != null && ctx.Length < 256;
+        }
+
+        private static bool CheckPointVar(byte[] p)
+        {
+            if ((p[PointBytes - 1] & 0x7F) != 0x00)
+            {
+                return false;
+            }
+
+            uint[] t = new uint[14];
+            Decode32(p, 0, t, 0, 14);
+            return !Nat.Gte(14, t, P);
+        }
+
+        private static bool CheckScalarVar(byte[] s)
+        {
+            if (s[ScalarBytes - 1] != 0x00)
+            {
+                return false;
+            }
+
+            uint[] n = new uint[ScalarUints];
+            DecodeScalar(s, 0, n);
+            return !Nat.Gte(ScalarUints, n, L);
+        }
+
+        private static uint Decode16(byte[] bs, int off)
+        {
+            uint n = bs[off];
+            n |= (uint)bs[++off] << 8;
+            return n;
+        }
+
+        private static uint Decode24(byte[] bs, int off)
+        {
+            uint n = bs[off];
+            n |= (uint)bs[++off] << 8;
+            n |= (uint)bs[++off] << 16;
+            return n;
+        }
+
+        private static uint Decode32(byte[] bs, int off)
+        {
+            uint n = bs[off];
+            n |= (uint)bs[++off] << 8;
+            n |= (uint)bs[++off] << 16;
+            n |= (uint)bs[++off] << 24;
+            return n;
+        }
+
+        private static void Decode32(byte[] bs, int bsOff, uint[] n, int nOff, int nLen)
+        {
+            for (int i = 0; i < nLen; ++i)
+            {
+                n[nOff + i] = Decode32(bs, bsOff + i * 4);
+            }
+        }
+
+        private static bool DecodePointVar(byte[] p, int pOff, bool negate, PointExt r)
+        {
+            byte[] py = Arrays.CopyOfRange(p, pOff, pOff + PointBytes);
+            if (!CheckPointVar(py))
+            {
+                return false;
+            }
+
+            int x_0 = (py[PointBytes - 1] & 0x80) >> 7;
+            py[PointBytes - 1] &= 0x7F;
+
+            X448Field.Decode(py, 0, r.y);
+
+            uint[] u = X448Field.Create();
+            uint[] v = X448Field.Create();
+
+            X448Field.Sqr(r.y, u);
+            X448Field.Mul(u, (uint)-C_d, v);
+            X448Field.Negate(u, u);
+            X448Field.AddOne(u);
+            X448Field.AddOne(v);
+
+            if (!X448Field.SqrtRatioVar(u, v, r.x))
+            {
+                return false;
+            }
+
+            X448Field.Normalize(r.x);
+            if (x_0 == 1 && X448Field.IsZeroVar(r.x))
+            {
+                return false;
+            }
+
+            if (negate ^ (x_0 != (r.x[0] & 1)))
+            {
+                X448Field.Negate(r.x, r.x);
+            }
+
+            PointExtendXY(r);
+            return true;
+        }
+
+        private static void DecodeScalar(byte[] k, int kOff, uint[] n)
+        {
+            Debug.Assert(k[kOff + ScalarBytes - 1] == 0x00);
+
+            Decode32(k, kOff, n, 0, ScalarUints);
+        }
+
+        private static void Dom4(ShakeDigest d, byte x, byte[] y)
+        {
+            d.BlockUpdate(Dom4Prefix, 0, Dom4Prefix.Length);
+            d.Update(x);
+            d.Update((byte)y.Length);
+            d.BlockUpdate(y, 0, y.Length);
+        }
+
+        private static void Encode24(uint n, byte[] bs, int off)
+        {
+            bs[off] = (byte)(n);
+            bs[++off] = (byte)(n >> 8);
+            bs[++off] = (byte)(n >> 16);
+        }
+
+        private static void Encode32(uint n, byte[] bs, int off)
+        {
+            bs[off] = (byte)(n);
+            bs[++off] = (byte)(n >> 8);
+            bs[++off] = (byte)(n >> 16);
+            bs[++off] = (byte)(n >> 24);
+        }
+
+        private static void Encode56(ulong n, byte[] bs, int off)
+        {
+            Encode32((uint)n, bs, off);
+            Encode24((uint)(n >> 32), bs, off + 4);
+        }
+
+        private static void EncodePoint(PointExt p, byte[] r, int rOff)
+        {
+            uint[] x = X448Field.Create();
+            uint[] y = X448Field.Create();
+
+            X448Field.Inv(p.z, y);
+            X448Field.Mul(p.x, y, x);
+            X448Field.Mul(p.y, y, y);
+            X448Field.Normalize(x);
+            X448Field.Normalize(y);
+
+            X448Field.Encode(y, r, rOff);
+            r[rOff + PointBytes - 1] = (byte)((x[0] & 1) << 7);
+        }
+
+        public static void GeneratePublicKey(byte[] sk, int skOff, byte[] pk, int pkOff)
+        {
+            ShakeDigest d = new ShakeDigest(256);
+            byte[] h = new byte[ScalarBytes * 2];
+
+            d.BlockUpdate(sk, skOff, SecretKeySize);
+            d.DoFinal(h, 0, h.Length);
+
+            byte[] s = new byte[ScalarBytes];
+            PruneScalar(h, 0, s);
+
+            ScalarMultBaseEncoded(s, pk, pkOff);
+        }
+
+        private static sbyte[] GetWnaf(uint[] n, int width)
+        {
+            Debug.Assert(n[ScalarUints - 1] >> 31 == 0U);
+
+            uint[] t = new uint[ScalarUints * 2];
+            {
+                uint c = 0;
+                int tPos = t.Length, i = ScalarUints;
+                while (--i >= 0)
+                {
+                    uint next = n[i];
+                    t[--tPos] = (next >> 16) | (c << 16);
+                    t[--tPos] = c = next;
+                }
+            }
+
+            sbyte[] ws = new sbyte[448];
+
+            uint pow2 = 1U << width;
+            uint mask = pow2 - 1U;
+            uint sign = pow2 >> 1;
+
+            uint carry = 0U;
+            int j = 0;
+            for (int i = 0; i < t.Length; ++i, j -= 16)
+            {
+                uint word = t[i];
+                while (j < 16)
+                {
+                    uint word16 = word >> j;
+                    uint bit = word16 & 1U;
+
+                    if (bit == carry)
+                    {
+                        ++j;
+                        continue;
+                    }
+
+                    uint digit = (word16 & mask) + carry;
+                    carry = digit & sign;
+                    digit -= (carry << 1);
+                    carry >>= (width - 1);
+
+                    ws[(i << 4) + j] = (sbyte)digit;
+
+                    j += width;
+                }
+            }
+
+            Debug.Assert(carry == 0);
+
+            return ws;
+        }
+
+        private static void ImplSign(ShakeDigest d, byte[] h, byte[] s, byte[] pk, int pkOff, byte[] ctx, byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
+        {
+            byte phflag = 0x00;
+
+            Dom4(d, phflag, ctx);
+            d.BlockUpdate(h, ScalarBytes, ScalarBytes);
+            d.BlockUpdate(m, mOff, mLen);
+            d.DoFinal(h, 0, h.Length);
+
+            byte[] r = ReduceScalar(h);
+            byte[] R = new byte[PointBytes];
+            ScalarMultBaseEncoded(r, R, 0);
+
+            Dom4(d, phflag, ctx);
+            d.BlockUpdate(R, 0, PointBytes);
+            d.BlockUpdate(pk, pkOff, PointBytes);
+            d.BlockUpdate(m, mOff, mLen);
+            d.DoFinal(h, 0, h.Length);
+
+            byte[] k = ReduceScalar(h);
+            byte[] S = CalculateS(r, k, s);
+
+            Array.Copy(R, 0, sig, sigOff, PointBytes);
+            Array.Copy(S, 0, sig, sigOff + PointBytes, ScalarBytes);
+        }
+
+        private static void PointAddVar(bool negate, PointExt p, PointExt r)
+        {
+            uint[] A = X448Field.Create();
+            uint[] B = X448Field.Create();
+            uint[] C = X448Field.Create();
+            uint[] D = X448Field.Create();
+            uint[] E = X448Field.Create();
+            uint[] F = X448Field.Create();
+            uint[] G = X448Field.Create();
+            uint[] H = X448Field.Create();
+
+            uint[] b, e, f, g;
+            if (negate)
+            {
+                b = E; e = B; f = G; g = F;
+                X448Field.Sub(p.y, p.x, H);
+            }
+            else
+            {
+                b = B; e = E; f = F; g = G;
+                X448Field.Add(p.y, p.x, H);
+            }
+
+            X448Field.Mul(p.z, r.z, A);
+            X448Field.Sqr(A, B);
+            X448Field.Mul(p.x, r.x, C);
+            X448Field.Mul(p.y, r.y, D);
+            X448Field.Mul(C, D, E);
+            X448Field.Mul(E, -C_d, E);
+    //        X448Field.Apm(B, E, F, G);
+            X448Field.Add(B, E, f);
+            X448Field.Sub(B, E, g);
+            X448Field.Add(r.x, r.y, E);
+            X448Field.Mul(H, E, H);
+    //        X448Field.Apm(D, C, B, E);
+            X448Field.Add(D, C, b);
+            X448Field.Sub(D, C, e);
+            X448Field.Carry(b);
+            X448Field.Sub(H, B, H);
+            X448Field.Mul(H, A, H);
+            X448Field.Mul(E, A, E);
+            X448Field.Mul(F, H, r.x);
+            X448Field.Mul(E, G, r.y);
+            X448Field.Mul(F, G, r.z);
+        }
+
+        private static void PointAddPrecomp(PointPrecomp p, PointExt r)
+        {
+            uint[] B = X448Field.Create();
+            uint[] C = X448Field.Create();
+            uint[] D = X448Field.Create();
+            uint[] E = X448Field.Create();
+            uint[] F = X448Field.Create();
+            uint[] G = X448Field.Create();
+            uint[] H = X448Field.Create();
+
+            X448Field.Sqr(r.z, B);
+            X448Field.Mul(p.x, r.x, C);
+            X448Field.Mul(p.y, r.y, D);
+            X448Field.Mul(C, D, E);
+            X448Field.Mul(E, -C_d, E);
+    //        X448Field.Apm(B, E, F, G);
+            X448Field.Add(B, E, F);
+            X448Field.Sub(B, E, G);
+            X448Field.Add(p.x, p.y, B);
+            X448Field.Add(r.x, r.y, E);
+            X448Field.Mul(B, E, H);
+    //        X448Field.Apm(D, C, B, E);
+            X448Field.Add(D, C, B);
+            X448Field.Sub(D, C, E);
+            X448Field.Carry(B);
+            X448Field.Sub(H, B, H);
+            X448Field.Mul(H, r.z, H);
+            X448Field.Mul(E, r.z, E);
+            X448Field.Mul(F, H, r.x);
+            X448Field.Mul(E, G, r.y);
+            X448Field.Mul(F, G, r.z);
+        }
+
+        private static PointExt PointCopy(PointExt p)
+        {
+            PointExt r = new PointExt();
+            X448Field.Copy(p.x, 0, r.x, 0);
+            X448Field.Copy(p.y, 0, r.y, 0);
+            X448Field.Copy(p.z, 0, r.z, 0);
+            return r;
+        }
+
+        private static void PointDouble(PointExt r)
+        {
+            uint[] B = X448Field.Create();
+            uint[] C = X448Field.Create();
+            uint[] D = X448Field.Create();
+            uint[] E = X448Field.Create();
+            uint[] H = X448Field.Create();
+            uint[] J = X448Field.Create();
+
+            X448Field.Add(r.x, r.y, B);
+            X448Field.Sqr(B, B);
+            X448Field.Sqr(r.x, C);
+            X448Field.Sqr(r.y, D);
+            X448Field.Add(C, D, E);
+            X448Field.Carry(E);
+            X448Field.Sqr(r.z, H);
+            X448Field.Add(H, H, H);
+            X448Field.Carry(H);
+            X448Field.Sub(E, H, J);
+            X448Field.Sub(B, E, B);
+            X448Field.Sub(C, D, C);
+            X448Field.Mul(B, J, r.x);
+            X448Field.Mul(E, C, r.y);
+            X448Field.Mul(E, J, r.z);
+        }
+
+        private static void PointExtendXY(PointExt p)
+        {
+            X448Field.One(p.z);
+        }
+
+        private static void PointLookup(int block, int index, PointPrecomp p)
+        {
+            Debug.Assert(0 <= block && block < PrecompBlocks);
+            Debug.Assert(0 <= index && index < PrecompPoints);
+
+            int off = block * PrecompPoints * 2 * X448Field.Size;
+
+            for (int i = 0; i < PrecompPoints; ++i)
+            {
+                int mask = ((i ^ index) - 1) >> 31;
+                Nat.CMov(X448Field.Size, mask, precompBase, off, p.x, 0);   off += X448Field.Size;
+                Nat.CMov(X448Field.Size, mask, precompBase, off, p.y, 0);   off += X448Field.Size;
+            }
+        }
+
+        private static PointExt[] PointPrecompVar(PointExt p, int count)
+        {
+            Debug.Assert(count > 0);
+
+            PointExt d = PointCopy(p);
+            PointDouble(d);
+
+            PointExt[] table = new PointExt[count];
+            table[0] = PointCopy(p);
+            for (int i = 1; i < count; ++i)
+            {
+                table[i] = PointCopy(table[i - 1]);
+                PointAddVar(false, d, table[i]);
+            }
+            return table;
+        }
+
+        private static void PointSetNeutral(PointExt p)
+        {
+            X448Field.Zero(p.x);
+            X448Field.One(p.y);
+            X448Field.One(p.z);
+        }
+
+        [MethodImpl(MethodImplOptions.Synchronized)]
+        public static void Precompute()
+        {
+            if (precompBase != null)
+            {
+                return;
+            }
+
+            PointExt p = new PointExt();
+            X448Field.Copy(B_x, 0, p.x, 0);
+            X448Field.Copy(B_y, 0, p.y, 0);
+            PointExtendXY(p);
+
+            precompBaseTable = PointPrecompVar(p, 1 << (WnafWidthBase - 2));
+
+            precompBase = new uint[PrecompBlocks * PrecompPoints * 2 * X448Field.Size];
+
+            int off = 0;
+            for (int b = 0; b < PrecompBlocks; ++b)
+            {
+                PointExt[] ds = new PointExt[PrecompTeeth];
+
+                PointExt sum = new PointExt();
+                PointSetNeutral(sum);
+
+                for (int t = 0; t < PrecompTeeth; ++t)
+                {
+                    PointAddVar(true, p, sum);
+                    PointDouble(p);
+
+                    ds[t] = PointCopy(p);
+
+                    for (int s = 1; s < PrecompSpacing; ++s)
+                    {
+                        PointDouble(p);
+                    }
+                }
+
+                PointExt[] points = new PointExt[PrecompPoints];
+                int k = 0;
+                points[k++] = sum;
+
+                for (int t = 0; t < (PrecompTeeth - 1); ++t)
+                {
+                    int size = 1 << t;
+                    for (int j = 0; j < size; ++j, ++k)
+                    {
+                        points[k] = PointCopy(points[k - size]);
+                        PointAddVar(false, ds[t], points[k]);
+                    }
+                }
+
+                Debug.Assert(k == PrecompPoints);
+
+                for (int i = 0; i < PrecompPoints; ++i)
+                {
+                    PointExt q = points[i];
+                    // TODO[ed448] Batch inversion
+                    X448Field.Inv(q.z, q.z);
+                    X448Field.Mul(q.x, q.z, q.x);
+                    X448Field.Mul(q.y, q.z, q.y);
+
+    //                X448Field.Normalize(q.x);
+    //                X448Field.Normalize(q.y);
+
+                    X448Field.Copy(q.x, 0, precompBase, off);   off += X448Field.Size;
+                    X448Field.Copy(q.y, 0, precompBase, off);   off += X448Field.Size;
+                }
+            }
+
+            Debug.Assert(off == precompBase.Length);
+        }
+
+        private static void PruneScalar(byte[] n, int nOff, byte[] r)
+        {
+            Array.Copy(n, nOff, r, 0, ScalarBytes);
+
+            r[0] &= 0xFC;
+            r[ScalarBytes - 2] |= 0x80;
+            r[ScalarBytes - 1] &= 0x00;
+        }
+
+        private static byte[] ReduceScalar(byte[] n)
+        {
+            ulong x00 =  Decode32(n,   0);          // x00:32/--
+            ulong x01 = (Decode24(n,   4) << 4);    // x01:28/--
+            ulong x02 =  Decode32(n,   7);          // x02:32/--
+            ulong x03 = (Decode24(n,  11) << 4);    // x03:28/--
+            ulong x04 =  Decode32(n,  14);          // x04:32/--
+            ulong x05 = (Decode24(n,  18) << 4);    // x05:28/--
+            ulong x06 =  Decode32(n,  21);          // x06:32/--
+            ulong x07 = (Decode24(n,  25) << 4);    // x07:28/--
+            ulong x08 =  Decode32(n,  28);          // x08:32/--
+            ulong x09 = (Decode24(n,  32) << 4);    // x09:28/--
+            ulong x10 =  Decode32(n,  35);          // x10:32/--
+            ulong x11 = (Decode24(n,  39) << 4);    // x11:28/--
+            ulong x12 =  Decode32(n,  42);          // x12:32/--
+            ulong x13 = (Decode24(n,  46) << 4);    // x13:28/--
+            ulong x14 =  Decode32(n,  49);          // x14:32/--
+            ulong x15 = (Decode24(n,  53) << 4);    // x15:28/--
+            ulong x16 =  Decode32(n,  56);          // x16:32/--
+            ulong x17 = (Decode24(n,  60) << 4);    // x17:28/--
+            ulong x18 =  Decode32(n,  63);          // x18:32/--
+            ulong x19 = (Decode24(n,  67) << 4);    // x19:28/--
+            ulong x20 =  Decode32(n,  70);          // x20:32/--
+            ulong x21 = (Decode24(n,  74) << 4);    // x21:28/--
+            ulong x22 =  Decode32(n,  77);          // x22:32/--
+            ulong x23 = (Decode24(n,  81) << 4);    // x23:28/--
+            ulong x24 =  Decode32(n,  84);          // x24:32/--
+            ulong x25 = (Decode24(n,  88) << 4);    // x25:28/--
+            ulong x26 =  Decode32(n,  91);          // x26:32/--
+            ulong x27 = (Decode24(n,  95) << 4);    // x27:28/--
+            ulong x28 =  Decode32(n,  98);          // x28:32/--
+            ulong x29 = (Decode24(n, 102) << 4);    // x29:28/--
+            ulong x30 =  Decode32(n, 105);          // x30:32/--
+            ulong x31 = (Decode24(n, 109) << 4);    // x31:28/--
+            ulong x32 =  Decode16(n, 112);          // x32:16/--
+
+    //        x32 += (x31 >> 28); x31 &= M28UL;
+            x16 += x32 * L4_0;                          // x16:42/--
+            x17 += x32 * L4_1;                          // x17:41/28
+            x18 += x32 * L4_2;                          // x18:43/42
+            x19 += x32 * L4_3;                          // x19:44/28
+            x20 += x32 * L4_4;                          // x20:43/--
+            x21 += x32 * L4_5;                          // x21:44/28
+            x22 += x32 * L4_6;                          // x22:43/41
+            x23 += x32 * L4_7;                          // x23:45/41
+
+            x31 += (x30 >> 28); x30 &= M28UL;           // x31:28/--, x30:28/--
+            x15 += x31 * L4_0;                          // x15:54/--
+            x16 += x31 * L4_1;                          // x16:53/42
+            x17 += x31 * L4_2;                          // x17:55/54
+            x18 += x31 * L4_3;                          // x18:56/44
+            x19 += x31 * L4_4;                          // x19:55/--
+            x20 += x31 * L4_5;                          // x20:56/43
+            x21 += x31 * L4_6;                          // x21:55/53
+            x22 += x31 * L4_7;                          // x22:57/53
+
+    //        x30 += (x29 >> 28); x29 &= M28UL;
+            x14 += x30 * L4_0;                          // x14:54/--
+            x15 += x30 * L4_1;                          // x15:54/53
+            x16 += x30 * L4_2;                          // x16:56/--
+            x17 += x30 * L4_3;                          // x17:57/--
+            x18 += x30 * L4_4;                          // x18:56/55
+            x19 += x30 * L4_5;                          // x19:56/55
+            x20 += x30 * L4_6;                          // x20:57/--
+            x21 += x30 * L4_7;                          // x21:57/56
+
+            x29 += (x28 >> 28); x28 &= M28UL;           // x29:28/--, x28:28/--
+            x13 += x29 * L4_0;                          // x13:54/--
+            x14 += x29 * L4_1;                          // x14:54/53
+            x15 += x29 * L4_2;                          // x15:56/--
+            x16 += x29 * L4_3;                          // x16:57/--
+            x17 += x29 * L4_4;                          // x17:57/55
+            x18 += x29 * L4_5;                          // x18:57/55
+            x19 += x29 * L4_6;                          // x19:57/52
+            x20 += x29 * L4_7;                          // x20:58/52
+
+    //        x28 += (x27 >> 28); x27 &= M28UL;
+            x12 += x28 * L4_0;                          // x12:54/--
+            x13 += x28 * L4_1;                          // x13:54/53
+            x14 += x28 * L4_2;                          // x14:56/--
+            x15 += x28 * L4_3;                          // x15:57/--
+            x16 += x28 * L4_4;                          // x16:57/55
+            x17 += x28 * L4_5;                          // x17:58/--
+            x18 += x28 * L4_6;                          // x18:58/--
+            x19 += x28 * L4_7;                          // x19:58/53
+
+            x27 += (x26 >> 28); x26 &= M28UL;           // x27:28/--, x26:28/--
+            x11 += x27 * L4_0;                          // x11:54/--
+            x12 += x27 * L4_1;                          // x12:54/53
+            x13 += x27 * L4_2;                          // x13:56/--
+            x14 += x27 * L4_3;                          // x14:57/--
+            x15 += x27 * L4_4;                          // x15:57/55
+            x16 += x27 * L4_5;                          // x16:58/--
+            x17 += x27 * L4_6;                          // x17:58/56
+            x18 += x27 * L4_7;                          // x18:59/--
+
+    //        x26 += (x25 >> 28); x25 &= M28UL;
+            x10 += x26 * L4_0;                          // x10:54/--
+            x11 += x26 * L4_1;                          // x11:54/53
+            x12 += x26 * L4_2;                          // x12:56/--
+            x13 += x26 * L4_3;                          // x13:57/--
+            x14 += x26 * L4_4;                          // x14:57/55
+            x15 += x26 * L4_5;                          // x15:58/--
+            x16 += x26 * L4_6;                          // x16:58/56
+            x17 += x26 * L4_7;                          // x17:59/--
+
+            x25 += (x24 >> 28); x24 &= M28UL;           // x25:28/--, x24:28/--
+            x09 += x25 * L4_0;                          // x09:54/--
+            x10 += x25 * L4_1;                          // x10:54/53
+            x11 += x25 * L4_2;                          // x11:56/--
+            x12 += x25 * L4_3;                          // x12:57/--
+            x13 += x25 * L4_4;                          // x13:57/55
+            x14 += x25 * L4_5;                          // x14:58/--
+            x15 += x25 * L4_6;                          // x15:58/56
+            x16 += x25 * L4_7;                          // x16:59/--
+
+            x21 += (x20 >> 28); x20 &= M28UL;           // x21:58/--, x20:28/--
+            x22 += (x21 >> 28); x21 &= M28UL;           // x22:57/54, x21:28/--
+            x23 += (x22 >> 28); x22 &= M28UL;           // x23:45/42, x22:28/--
+            x24 += (x23 >> 28); x23 &= M28UL;           // x24:28/18, x23:28/--
+
+            x08 += x24 * L4_0;                          // x08:54/--
+            x09 += x24 * L4_1;                          // x09:55/--
+            x10 += x24 * L4_2;                          // x10:56/46
+            x11 += x24 * L4_3;                          // x11:57/46
+            x12 += x24 * L4_4;                          // x12:57/55
+            x13 += x24 * L4_5;                          // x13:58/--
+            x14 += x24 * L4_6;                          // x14:58/56
+            x15 += x24 * L4_7;                          // x15:59/--
+
+            x07 += x23 * L4_0;                          // x07:54/--
+            x08 += x23 * L4_1;                          // x08:54/53
+            x09 += x23 * L4_2;                          // x09:56/53
+            x10 += x23 * L4_3;                          // x10:57/46
+            x11 += x23 * L4_4;                          // x11:57/55
+            x12 += x23 * L4_5;                          // x12:58/--
+            x13 += x23 * L4_6;                          // x13:58/56
+            x14 += x23 * L4_7;                          // x14:59/--
+
+            x06 += x22 * L4_0;                          // x06:54/--
+            x07 += x22 * L4_1;                          // x07:54/53
+            x08 += x22 * L4_2;                          // x08:56/--
+            x09 += x22 * L4_3;                          // x09:57/53
+            x10 += x22 * L4_4;                          // x10:57/55
+            x11 += x22 * L4_5;                          // x11:58/--
+            x12 += x22 * L4_6;                          // x12:58/56
+            x13 += x22 * L4_7;                          // x13:59/--
+
+            x18 += (x17 >> 28); x17 &= M28UL;           // x18:59/31, x17:28/--
+            x19 += (x18 >> 28); x18 &= M28UL;           // x19:58/54, x18:28/--
+            x20 += (x19 >> 28); x19 &= M28UL;           // x20:30/29, x19:28/--
+            x21 += (x20 >> 28); x20 &= M28UL;           // x21:28/03, x20:28/--
+
+            x05 += x21 * L4_0;                          // x05:54/--
+            x06 += x21 * L4_1;                          // x06:55/--
+            x07 += x21 * L4_2;                          // x07:56/31
+            x08 += x21 * L4_3;                          // x08:57/31
+            x09 += x21 * L4_4;                          // x09:57/56
+            x10 += x21 * L4_5;                          // x10:58/--
+            x11 += x21 * L4_6;                          // x11:58/56
+            x12 += x21 * L4_7;                          // x12:59/--
+
+            x04 += x20 * L4_0;                          // x04:54/--
+            x05 += x20 * L4_1;                          // x05:54/53
+            x06 += x20 * L4_2;                          // x06:56/53
+            x07 += x20 * L4_3;                          // x07:57/31
+            x08 += x20 * L4_4;                          // x08:57/55
+            x09 += x20 * L4_5;                          // x09:58/--
+            x10 += x20 * L4_6;                          // x10:58/56
+            x11 += x20 * L4_7;                          // x11:59/--
+
+            x03 += x19 * L4_0;                          // x03:54/--
+            x04 += x19 * L4_1;                          // x04:54/53
+            x05 += x19 * L4_2;                          // x05:56/--
+            x06 += x19 * L4_3;                          // x06:57/53
+            x07 += x19 * L4_4;                          // x07:57/55
+            x08 += x19 * L4_5;                          // x08:58/--
+            x09 += x19 * L4_6;                          // x09:58/56
+            x10 += x19 * L4_7;                          // x10:59/--
+
+            x15 += (x14 >> 28); x14 &= M28UL;           // x15:59/31, x14:28/--
+            x16 += (x15 >> 28); x15 &= M28UL;           // x16:59/32, x15:28/--
+            x17 += (x16 >> 28); x16 &= M28UL;           // x17:31/29, x16:28/--
+            x18 += (x17 >> 28); x17 &= M28UL;           // x18:28/04, x17:28/--
+
+            x02 += x18 * L4_0;                          // x02:54/--
+            x03 += x18 * L4_1;                          // x03:55/--
+            x04 += x18 * L4_2;                          // x04:56/32
+            x05 += x18 * L4_3;                          // x05:57/32
+            x06 += x18 * L4_4;                          // x06:57/56
+            x07 += x18 * L4_5;                          // x07:58/--
+            x08 += x18 * L4_6;                          // x08:58/56
+            x09 += x18 * L4_7;                          // x09:59/--
+
+            x01 += x17 * L4_0;                          // x01:54/--
+            x02 += x17 * L4_1;                          // x02:54/53
+            x03 += x17 * L4_2;                          // x03:56/53
+            x04 += x17 * L4_3;                          // x04:57/32
+            x05 += x17 * L4_4;                          // x05:57/55
+            x06 += x17 * L4_5;                          // x06:58/--
+            x07 += x17 * L4_6;                          // x07:58/56
+            x08 += x17 * L4_7;                          // x08:59/--
+
+            x16 *= 4;
+            x16 += (x15 >> 26); x15 &= M26UL;
+            x16 += 1;                                   // x16:30/01
+
+            x00 += x16 * L_0;
+            x01 += x16 * L_1;
+            x02 += x16 * L_2;
+            x03 += x16 * L_3;
+            x04 += x16 * L_4;
+            x05 += x16 * L_5;
+            x06 += x16 * L_6;
+            x07 += x16 * L_7;
+
+            x01 += (x00 >> 28); x00 &= M28UL;
+            x02 += (x01 >> 28); x01 &= M28UL;
+            x03 += (x02 >> 28); x02 &= M28UL;
+            x04 += (x03 >> 28); x03 &= M28UL;
+            x05 += (x04 >> 28); x04 &= M28UL;
+            x06 += (x05 >> 28); x05 &= M28UL;
+            x07 += (x06 >> 28); x06 &= M28UL;
+            x08 += (x07 >> 28); x07 &= M28UL;
+            x09 += (x08 >> 28); x08 &= M28UL;
+            x10 += (x09 >> 28); x09 &= M28UL;
+            x11 += (x10 >> 28); x10 &= M28UL;
+            x12 += (x11 >> 28); x11 &= M28UL;
+            x13 += (x12 >> 28); x12 &= M28UL;
+            x14 += (x13 >> 28); x13 &= M28UL;
+            x15 += (x14 >> 28); x14 &= M28UL;
+            x16  = (x15 >> 26); x15 &= M26UL;
+
+            x16 -= 1;
+
+            Debug.Assert(x16 == 0UL || x16 == ulong.MaxValue);
+
+            x00 -= x16 & L_0;
+            x01 -= x16 & L_1;
+            x02 -= x16 & L_2;
+            x03 -= x16 & L_3;
+            x04 -= x16 & L_4;
+            x05 -= x16 & L_5;
+            x06 -= x16 & L_6;
+            x07 -= x16 & L_7;
+
+            x01 += (ulong)((long)x00 >> 28); x00 &= M28UL;
+            x02 += (ulong)((long)x01 >> 28); x01 &= M28UL;
+            x03 += (ulong)((long)x02 >> 28); x02 &= M28UL;
+            x04 += (ulong)((long)x03 >> 28); x03 &= M28UL;
+            x05 += (ulong)((long)x04 >> 28); x04 &= M28UL;
+            x06 += (ulong)((long)x05 >> 28); x05 &= M28UL;
+            x07 += (ulong)((long)x06 >> 28); x06 &= M28UL;
+            x08 += (ulong)((long)x07 >> 28); x07 &= M28UL;
+            x09 += (ulong)((long)x08 >> 28); x08 &= M28UL;
+            x10 += (ulong)((long)x09 >> 28); x09 &= M28UL;
+            x11 += (ulong)((long)x10 >> 28); x10 &= M28UL;
+            x12 += (ulong)((long)x11 >> 28); x11 &= M28UL;
+            x13 += (ulong)((long)x12 >> 28); x12 &= M28UL;
+            x14 += (ulong)((long)x13 >> 28); x13 &= M28UL;
+            x15 += (ulong)((long)x14 >> 28); x14 &= M28UL;
+
+            Debug.Assert(x15 >> 26 == 0UL);
+
+            byte[] r = new byte[ScalarBytes];
+            Encode56(x00 | (x01 << 28), r,  0);
+            Encode56(x02 | (x03 << 28), r,  7);
+            Encode56(x04 | (x05 << 28), r, 14);
+            Encode56(x06 | (x07 << 28), r, 21);
+            Encode56(x08 | (x09 << 28), r, 28);
+            Encode56(x10 | (x11 << 28), r, 35);
+            Encode56(x12 | (x13 << 28), r, 42);
+            Encode56(x14 | (x15 << 28), r, 49);
+    //        r[ScalarBytes - 1] = 0;
+            return r;
+        }
+
+        private static void ScalarMultBase(byte[] k, PointExt r)
+        {
+            Precompute();
+
+            PointSetNeutral(r);
+
+            uint[] n = new uint[ScalarUints + 1];
+            DecodeScalar(k, 0, n);
+
+            // Recode the scalar into signed-digit form
+            {
+                n[ScalarUints] = 4U + Nat.CAdd(ScalarUints, ~(int)n[0] & 1, n, L, n);
+                uint c = Nat.ShiftDownBit(n.Length, n, 0);
+                Debug.Assert(c == (1U << 31));
+            }
+
+            PointPrecomp p = new PointPrecomp();
+
+            int cOff = PrecompSpacing - 1;
+            for (;;)
+            {
+                int tPos = cOff;
+
+                for (int b = 0; b < PrecompBlocks; ++b)
+                {
+                    uint w = 0;
+                    for (int t = 0; t < PrecompTeeth; ++t)
+                    {
+                        uint tBit = (n[tPos >> 5] >> (tPos & 0x1F)) & 1U;
+                        w |= tBit << t;
+                        tPos += PrecompSpacing;
+                    }
+
+                    int sign = (int)(w >> (PrecompTeeth - 1)) & 1;
+                    int abs = ((int)w ^ -sign) & PrecompMask;
+
+                    Debug.Assert(sign == 0 || sign == 1);
+                    Debug.Assert(0 <= abs && abs < PrecompPoints);
+
+                    PointLookup(b, abs, p);
+
+                    X448Field.CNegate(sign, p.x);
+
+                    PointAddPrecomp(p, r);
+                }
+
+                if (--cOff < 0)
+                {
+                    break;
+                }
+
+                PointDouble(r);
+            }
+        }
+
+        private static void ScalarMultBaseEncoded(byte[] k, byte[] r, int rOff)
+        {
+            PointExt p = new PointExt();
+            ScalarMultBase(k, p);
+            EncodePoint(p, r, rOff);
+        }
+
+        private static void ScalarMultStraussVar(uint[] nb, uint[] np, PointExt p, PointExt r)
+        {
+            Precompute();
+
+            int width = 5;
+
+            sbyte[] ws_b = GetWnaf(nb, WnafWidthBase);
+            sbyte[] ws_p = GetWnaf(np, width);
+
+            PointExt[] tp = PointPrecompVar(p, 1 << (width - 2));
+
+            PointSetNeutral(r);
+
+            int bit = 447;
+            while (bit > 0 && (ws_b[bit] | ws_p[bit]) == 0)
+            {
+                --bit;
+            }
+
+            for (;;)
+            {
+                int wb = ws_b[bit];
+                if (wb != 0)
+                {
+                    int sign = wb >> 31;
+                    int index = (wb ^ sign) >> 1;
+
+                    PointAddVar((sign != 0), precompBaseTable[index], r);
+                }
+
+                int wp = ws_p[bit];
+                if (wp != 0)
+                {
+                    int sign = wp >> 31;
+                    int index = (wp ^ sign) >> 1;
+
+                    PointAddVar((sign != 0), tp[index], r);
+                }
+
+                if (--bit < 0)
+                {
+                    break;
+                }
+
+                PointDouble(r);
+            }
+        }
+
+        public static void Sign(byte[] sk, int skOff, byte[] ctx, byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
+        {
+            if (!CheckContextVar(ctx))
+            {
+                throw new ArgumentException("ctx");
+            }
+
+            ShakeDigest d = new ShakeDigest(256);
+            byte[] h = new byte[ScalarBytes * 2];
+
+            d.BlockUpdate(sk, skOff, SecretKeySize);
+            d.DoFinal(h, 0, h.Length);
+
+            byte[] s = new byte[ScalarBytes];
+            PruneScalar(h, 0, s);
+
+            byte[] pk = new byte[PointBytes];
+            ScalarMultBaseEncoded(s, pk, 0);
+
+            ImplSign(d, h, s, pk, 0, ctx, m, mOff, mLen, sig, sigOff);
+        }
+
+        public static void Sign(byte[] sk, int skOff, byte[] pk, int pkOff, byte[] ctx, byte[] m, int mOff, int mLen, byte[] sig, int sigOff)
+        {
+            if (!CheckContextVar(ctx))
+            {
+                throw new ArgumentException("ctx");
+            }
+
+            ShakeDigest d = new ShakeDigest(256);
+            byte[] h = new byte[ScalarBytes * 2];
+
+            d.BlockUpdate(sk, skOff, SecretKeySize);
+            d.DoFinal(h, 0, h.Length);
+
+            byte[] s = new byte[ScalarBytes];
+            PruneScalar(h, 0, s);
+
+            ImplSign(d, h, s, pk, pkOff, ctx, m, mOff, mLen, sig, sigOff);
+        }
+
+        public static bool Verify(byte[] sig, int sigOff, byte[] pk, int pkOff, byte[] ctx, byte[] m, int mOff, int mLen)
+        {
+            if (!CheckContextVar(ctx))
+            {
+                throw new ArgumentException("ctx");
+            }
+
+            byte[] R = Arrays.CopyOfRange(sig, sigOff, sigOff + PointBytes);
+            byte[] S = Arrays.CopyOfRange(sig, sigOff + PointBytes, sigOff + SignatureSize);
+
+            if (!CheckPointVar(R))
+            {
+                return false;
+            }
+            if (!CheckScalarVar(S))
+            {
+                return false;
+            }
+
+            PointExt pA = new PointExt();
+            if (!DecodePointVar(pk, pkOff, true, pA))
+            {
+                return false;
+            }
+
+            byte phflag = 0x00;
+
+            ShakeDigest d = new ShakeDigest(256);
+            byte[] h = new byte[ScalarBytes * 2];
+
+            Dom4(d, phflag, ctx);
+            d.BlockUpdate(R, 0, PointBytes);
+            d.BlockUpdate(pk, pkOff, PointBytes);
+            d.BlockUpdate(m, mOff, mLen);
+            d.DoFinal(h, 0, h.Length);
+
+            byte[] k = ReduceScalar(h);
+
+            uint[] nS = new uint[ScalarUints];
+            DecodeScalar(S, 0, nS);
+
+            uint[] nA = new uint[ScalarUints];
+            DecodeScalar(k, 0, nA);
+
+            PointExt pR = new PointExt();
+            ScalarMultStraussVar(nS, nA, pA, pR);
+
+            byte[] check = new byte[PointBytes];
+            EncodePoint(pR, check, 0);
+
+            return Arrays.AreEqual(check, R);
+        }
+    }
+}
diff --git a/crypto/src/math/raw/Interleave.cs b/crypto/src/math/raw/Interleave.cs
index d21840644..591ba3f15 100644
--- a/crypto/src/math/raw/Interleave.cs
+++ b/crypto/src/math/raw/Interleave.cs
@@ -6,6 +6,7 @@ namespace Org.BouncyCastle.Math.Raw
     {
         private const ulong M32 = 0x55555555UL;
         private const ulong M64 = 0x5555555555555555UL;
+        private const ulong M64R = 0xAAAAAAAAAAAAAAAAUL;
 
         /*
          * This expands 8 bit indices into 16 bit contents (high bit 14), by inserting 0s between bits.
@@ -92,6 +93,65 @@ namespace Org.BouncyCastle.Math.Raw
             z[zOff + 1] = (x >> 1) & M64;
         }
 
+        internal static void Expand64To128Rev(ulong x, ulong[] z, int zOff)
+        {
+            // "shuffle" low half to even bits and high half to odd bits
+            ulong t;
+            t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16));
+            t = (x ^ (x >>  8)) & 0x0000FF000000FF00UL; x ^= (t ^ (t <<  8));
+            t = (x ^ (x >>  4)) & 0x00F000F000F000F0UL; x ^= (t ^ (t <<  4));
+            t = (x ^ (x >>  2)) & 0x0C0C0C0C0C0C0C0CUL; x ^= (t ^ (t <<  2));
+            t = (x ^ (x >>  1)) & 0x2222222222222222UL; x ^= (t ^ (t <<  1));
+
+            z[zOff]     = (x     ) & M64R;
+            z[zOff + 1] = (x << 1) & M64R;
+        }
+
+        internal static uint Shuffle(uint x)
+        {
+            // "shuffle" low half to even bits and high half to odd bits
+            uint t;
+            t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8));
+            t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4));
+            t = (x ^ (x >> 2)) & 0x0C0C0C0CU; x ^= (t ^ (t << 2));
+            t = (x ^ (x >> 1)) & 0x22222222U; x ^= (t ^ (t << 1));
+            return x;
+        }
+
+        internal static ulong Shuffle(ulong x)
+        {
+            // "shuffle" low half to even bits and high half to odd bits
+            ulong t;
+            t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16));
+            t = (x ^ (x >>  8)) & 0x0000FF000000FF00UL; x ^= (t ^ (t <<  8));
+            t = (x ^ (x >>  4)) & 0x00F000F000F000F0UL; x ^= (t ^ (t <<  4));
+            t = (x ^ (x >>  2)) & 0x0C0C0C0C0C0C0C0CUL; x ^= (t ^ (t <<  2));
+            t = (x ^ (x >>  1)) & 0x2222222222222222UL; x ^= (t ^ (t <<  1));
+            return x;
+        }
+
+        internal static uint Shuffle2(uint x)
+        {
+            // "shuffle" (twice) low half to even bits and high half to odd bits
+            uint t;
+            t = (x ^ (x >>  7)) & 0x00AA00AAU; x ^= (t ^ (t <<  7));
+            t = (x ^ (x >> 14)) & 0x0000CCCCU; x ^= (t ^ (t << 14));
+            t = (x ^ (x >>  4)) & 0x00F000F0U; x ^= (t ^ (t <<  4));
+            t = (x ^ (x >>  8)) & 0x0000FF00U; x ^= (t ^ (t <<  8));
+            return x;
+        }
+
+        internal static uint Unshuffle(uint x)
+        {
+            // "unshuffle" even bits to low half and odd bits to high half
+            uint t;
+            t = (x ^ (x >> 1)) & 0x22222222U; x ^= (t ^ (t << 1));
+            t = (x ^ (x >> 2)) & 0x0C0C0C0CU; x ^= (t ^ (t << 2));
+            t = (x ^ (x >> 4)) & 0x00F000F0U; x ^= (t ^ (t << 4));
+            t = (x ^ (x >> 8)) & 0x0000FF00U; x ^= (t ^ (t << 8));
+            return x;
+        }
+
         internal static ulong Unshuffle(ulong x)
         {
             // "unshuffle" even bits to low half and odd bits to high half
@@ -103,5 +163,16 @@ namespace Org.BouncyCastle.Math.Raw
             t = (x ^ (x >> 16)) & 0x00000000FFFF0000UL; x ^= (t ^ (t << 16));
             return x;
         }
+
+        internal static uint Unshuffle2(uint x)
+        {
+            // "unshuffle" (twice) even bits to low half and odd bits to high half
+            uint t;
+            t = (x ^ (x >>  8)) & 0x0000FF00U; x ^= (t ^ (t <<  8));
+            t = (x ^ (x >>  4)) & 0x00F000F0U; x ^= (t ^ (t <<  4));
+            t = (x ^ (x >> 14)) & 0x0000CCCCU; x ^= (t ^ (t << 14));
+            t = (x ^ (x >>  7)) & 0x00AA00AAU; x ^= (t ^ (t <<  7));
+            return x;
+        }
     }
 }
diff --git a/crypto/src/math/raw/Nat.cs b/crypto/src/math/raw/Nat.cs
index cf6516c61..7ca60278a 100644
--- a/crypto/src/math/raw/Nat.cs
+++ b/crypto/src/math/raw/Nat.cs
@@ -195,6 +195,64 @@ namespace Org.BouncyCastle.Math.Raw
             return c == 0 ? 0 : IncAt(len, z, zOff, 1);
         }
 
+        public static uint CAdd(int len, int mask, uint[] x, uint[] y, uint[] z)
+        {
+            uint MASK = (uint)-(mask & 1);
+
+            ulong c = 0;
+            for (int i = 0; i < len; ++i)
+            {
+                c += (ulong)x[i] + (y[i] & MASK);
+                z[i] = (uint)c;
+                c >>= 32;
+            }
+            return (uint)c;
+        }
+
+        public static void CMov(int len, int mask, uint[] x, int xOff, uint[] z, int zOff)
+        {
+            uint MASK = (uint)-(mask & 1);
+
+            for (int i = 0; i < len; ++i)
+            {
+                uint z_i = z[zOff + i], diff = z_i ^ x[xOff + i];
+                z_i ^= (diff & MASK);
+                z[zOff + i] = z_i;
+            }
+
+            //uint half = 0x55555555U, rest = half << (-(int)MASK);
+
+            //for (int i = 0; i < len; ++i)
+            //{
+            //    uint z_i = z[zOff + i], diff = z_i ^ x[xOff + i];
+            //    z_i ^= (diff & half);
+            //    z_i ^= (diff & rest);
+            //    z[zOff + i] = z_i;
+            //}
+        }
+
+        public static void CMov(int len, int mask, int[] x, int xOff, int[] z, int zOff)
+        {
+            mask = -(mask & 1);
+
+            for (int i = 0; i < len; ++i)
+            {
+                int z_i = z[zOff + i], diff = z_i ^ x[xOff + i];
+                z_i ^= (diff & mask);
+                z[zOff + i] = z_i;
+            }
+
+            //int half = 0x55555555, rest = half << (-mask);
+
+            //for (int i = 0; i < len; ++i)
+            //{
+            //    int z_i = z[zOff + i], diff = z_i ^ x[xOff + i];
+            //    z_i ^= (diff & half);
+            //    z_i ^= (diff & rest);
+            //    z[zOff + i] = z_i;
+            //}
+        }
+
         public static void Copy(int len, uint[] x, uint[] z)
         {
             Array.Copy(x, 0, z, 0, len);
@@ -448,6 +506,33 @@ namespace Org.BouncyCastle.Math.Raw
             }
         }
 
+        public static uint MulAddTo(int len, uint[] x, uint[] y, uint[] zz)
+        {
+            ulong zc = 0;
+            for (int i = 0; i < len; ++i)
+            {
+                ulong c = MulWordAddTo(len, x[i], y, 0, zz, i) & M;
+                c += zc + (zz[i + len] & M);
+                zz[i + len] = (uint)c;
+                zc = c >> 32;
+            }
+            return (uint)zc;
+        }
+
+        public static uint MulAddTo(int len, uint[] x, int xOff, uint[] y, int yOff, uint[] zz, int zzOff)
+        {
+            ulong zc = 0;
+            for (int i = 0; i < len; ++i)
+            {
+                ulong c = MulWordAddTo(len, x[xOff + i], y, yOff, zz, zzOff) & M;
+                c += zc + (zz[zzOff + len] & M);
+                zz[zzOff + len] = (uint)c;
+                zc = c >> 32;
+                ++zzOff;
+            }
+            return (uint)zc;
+        }
+
         public static uint Mul31BothAdd(int len, uint a, uint[] x, uint b, uint[] y, uint[] z, int zOff)
         {
             ulong c = 0, aVal = (ulong)a, bVal = (ulong)b;
diff --git a/crypto/src/openpgp/PgpUtilities.cs b/crypto/src/openpgp/PgpUtilities.cs
index 5ea2907e8..039aa5893 100644
--- a/crypto/src/openpgp/PgpUtilities.cs
+++ b/crypto/src/openpgp/PgpUtilities.cs
@@ -356,7 +356,7 @@ namespace Org.BouncyCastle.Bcpg.OpenPgp
         {
             PgpLiteralDataGenerator lData = new PgpLiteralDataGenerator();
 			Stream pOut = lData.Open(output, fileType, file.Name, file.Length, file.LastWriteTime);
-			PipeFileContents(file, pOut, 4096);
+			PipeFileContents(file, pOut, 32768);
         }
 
 		/// <summary>Write out the passed in file as a literal data packet in partial packet format.</summary>
@@ -376,15 +376,22 @@ namespace Org.BouncyCastle.Bcpg.OpenPgp
 			FileStream inputStream = file.OpenRead();
 			byte[] buf = new byte[bufSize];
 
-			int len;
-            while ((len = inputStream.Read(buf, 0, buf.Length)) > 0)
+            try
             {
-                pOut.Write(buf, 0, len);
+			    int len;
+                while ((len = inputStream.Read(buf, 0, buf.Length)) > 0)
+                {
+                    pOut.Write(buf, 0, len);
+                }
             }
+            finally
+            {
+                Array.Clear(buf, 0, buf.Length);
 
-            Platform.Dispose(pOut);
-            Platform.Dispose(inputStream);
-		}
+                Platform.Dispose(pOut);
+                Platform.Dispose(inputStream);
+            }
+        }
 #endif
 
 		private const int ReadAhead = 60;
diff --git a/crypto/test/src/crypto/test/ECGOST3410Test.cs b/crypto/test/src/crypto/test/ECGOST3410Test.cs
index 5efa75169..fa79e58d9 100644
--- a/crypto/test/src/crypto/test/ECGOST3410Test.cs
+++ b/crypto/test/src/crypto/test/ECGOST3410Test.cs
@@ -56,7 +56,7 @@ namespace Org.BouncyCastle.Crypto.Tests
                 curve.CreatePoint(
                     new BigInteger("2"), // x
                     new BigInteger("4018974056539037503335449422937059775635739389905545080690979365213431566280")), // y
-                mod_q);
+                mod_q, BigInteger.One);
 
             ECPrivateKeyParameters priKey = new ECPrivateKeyParameters(
                 "ECGOST3410",
@@ -127,7 +127,7 @@ namespace Org.BouncyCastle.Crypto.Tests
                 curve.CreatePoint(
                     new BigInteger("2"), // x
                     new BigInteger("4018974056539037503335449422937059775635739389905545080690979365213431566280")), // y
-                mod_q);
+                mod_q, BigInteger.One);
 
             ECKeyPairGenerator          pGen = new ECKeyPairGenerator();
             ECKeyGenerationParameters   genParam = new ECKeyGenerationParameters(
@@ -184,7 +184,7 @@ namespace Org.BouncyCastle.Crypto.Tests
                 curve.CreatePoint(
                     new BigInteger("1"), // x
                     new BigInteger("64033881142927202683649881450433473985931760268884941288852745803908878638612")), // y
-                mod_q);
+                mod_q, BigInteger.One);
 
             ECKeyPairGenerator pGen = new ECKeyPairGenerator("ECGOST3410");
             ECKeyGenerationParameters genParam = new ECKeyGenerationParameters(
@@ -234,7 +234,7 @@ namespace Org.BouncyCastle.Crypto.Tests
                 curve.CreatePoint(
                     new BigInteger("1"), // x
                     new BigInteger("28792665814854611296992347458380284135028636778229113005756334730996303888124")), // y
-                mod_q);
+                mod_q, BigInteger.One);
 
             ECKeyPairGenerator pGen = new ECKeyPairGenerator("ECGOST3410");
             ECKeyGenerationParameters genParam = new ECKeyGenerationParameters(
@@ -284,7 +284,7 @@ namespace Org.BouncyCastle.Crypto.Tests
                 curve.CreatePoint(
                     new BigInteger("0"), // x
                     new BigInteger("29818893917731240733471273240314769927240550812383695689146495261604565990247")), // y
-                mod_q);
+                mod_q, BigInteger.One);
 
             ECKeyPairGenerator pGen = new ECKeyPairGenerator("ECGOST3410");
             ECKeyGenerationParameters genParam = new ECKeyGenerationParameters(
diff --git a/crypto/test/src/crypto/test/ECIESTest.cs b/crypto/test/src/crypto/test/ECIESTest.cs
index f17e6957a..4957e7e27 100644
--- a/crypto/test/src/crypto/test/ECIESTest.cs
+++ b/crypto/test/src/crypto/test/ECIESTest.cs
@@ -46,9 +46,9 @@ namespace Org.BouncyCastle.Crypto.Tests
                 n, BigInteger.One);
 
             ECDomainParameters parameters = new ECDomainParameters(
-                    curve,
-                    curve.DecodePoint(Hex.Decode("03188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012")), // G
-                    n);
+                curve,
+                curve.DecodePoint(Hex.Decode("03188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012")), // G
+                n, BigInteger.One);
 
             ECPrivateKeyParameters priKey = new ECPrivateKeyParameters(
                 "ECDH",
@@ -220,9 +220,9 @@ namespace Org.BouncyCastle.Crypto.Tests
                 n, BigInteger.One);
 
             ECDomainParameters parameters = new ECDomainParameters(
-                    curve,
-                    curve.DecodePoint(Hex.Decode("03188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012")), // G
-                    n);
+                curve,
+                curve.DecodePoint(Hex.Decode("03188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012")), // G
+                n, BigInteger.One);
 
             ECKeyPairGenerator eGen = new ECKeyPairGenerator();
             KeyGenerationParameters gParam = new ECKeyGenerationParameters(parameters, new SecureRandom());
diff --git a/crypto/test/src/crypto/test/ECNRTest.cs b/crypto/test/src/crypto/test/ECNRTest.cs
index 180b33560..ab4800221 100644
--- a/crypto/test/src/crypto/test/ECNRTest.cs
+++ b/crypto/test/src/crypto/test/ECNRTest.cs
@@ -49,7 +49,7 @@ namespace Org.BouncyCastle.Crypto.Tests
             ECDomainParameters parameters = new ECDomainParameters(
                 curve,
                 curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                n);
+                n, BigInteger.One);
 
             ECPrivateKeyParameters priKey = new ECPrivateKeyParameters(
                 new BigInteger("876300101507107567501066130761671078357010671067781776716671676178726717"), // d
diff --git a/crypto/test/src/crypto/test/ECTest.cs b/crypto/test/src/crypto/test/ECTest.cs
index 980d04d6c..f4dd4dce2 100644
--- a/crypto/test/src/crypto/test/ECTest.cs
+++ b/crypto/test/src/crypto/test/ECTest.cs
@@ -5,6 +5,7 @@ using NUnit.Framework;
 using Org.BouncyCastle.Asn1.Nist;
 using Org.BouncyCastle.Asn1.Sec;
 using Org.BouncyCastle.Asn1.X9;
+using Org.BouncyCastle.Crypto.EC;
 using Org.BouncyCastle.Math;
 using Org.BouncyCastle.Math.EC;
 using Org.BouncyCastle.Security;
@@ -52,7 +53,7 @@ namespace Org.BouncyCastle.Crypto.Tests
             ECDomainParameters parameters = new ECDomainParameters(
                 curve,
                 curve.DecodePoint(Hex.Decode("03188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012")), // G
-                n);
+                n, BigInteger.One);
 
             ECPrivateKeyParameters priKey = new ECPrivateKeyParameters(
                 "ECDSA",
@@ -98,12 +99,8 @@ namespace Org.BouncyCastle.Crypto.Tests
         [Test]
         public void TestDecode()
         {
-            FpCurve curve = new FpCurve(
-                new BigInteger("6277101735386680763835789423207666416083908700390324961279"), // q
-                new BigInteger("fffffffffffffffffffffffffffffffefffffffffffffffc", 16), // a
-                new BigInteger("64210519e59c80e70fa7e9ab72243049feb8deecc146b9b1", 16)); // b
-
-            ECPoint p = curve.DecodePoint(Hex.Decode("03188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012")).Normalize();
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("prime192v1");
+            ECPoint p = x9.G;
 
             if (!p.AffineXCoord.ToBigInteger().Equals(new BigInteger("188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012", 16)))
             {
@@ -115,7 +112,7 @@ namespace Org.BouncyCastle.Crypto.Tests
                 Fail("y uncompressed incorrectly");
             }
 
-            byte[] encoding = p.GetEncoded();
+            byte[] encoding = p.GetEncoded(true);
 
             if (!AreEqual(encoding, Hex.Decode("03188da80eb03090f67cbf20eb43a18800f4ff0afd82ff1012")))
             {
@@ -149,7 +146,7 @@ namespace Org.BouncyCastle.Crypto.Tests
             ECDomainParameters parameters = new ECDomainParameters(
                 curve,
                 curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                n);
+                n, BigInteger.One);
 
             ECPrivateKeyParameters priKey = new ECPrivateKeyParameters(
                 "ECDSA",
@@ -651,7 +648,7 @@ namespace Org.BouncyCastle.Crypto.Tests
             ECDomainParameters parameters = new ECDomainParameters(
                 curve,
                 curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                n);
+                n, BigInteger.One);
 
             ECKeyPairGenerator pGen = new ECKeyPairGenerator();
             ECKeyGenerationParameters genParam = new ECKeyGenerationParameters(
@@ -683,7 +680,7 @@ namespace Org.BouncyCastle.Crypto.Tests
          * Basic Key Agreement Test
          */
         [Test]
-        public void TestECBasicAgreementTest()
+        public void TestECDHBasicAgreement()
         {
             SecureRandom random = new SecureRandom();
 
@@ -698,7 +695,7 @@ namespace Org.BouncyCastle.Crypto.Tests
             ECDomainParameters parameters = new ECDomainParameters(
                 curve,
                 curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                n);
+                n, BigInteger.One);
 
             ECKeyPairGenerator pGen = new ECKeyPairGenerator();
             ECKeyGenerationParameters genParam = new ECKeyGenerationParameters(parameters, random);
@@ -744,6 +741,35 @@ namespace Org.BouncyCastle.Crypto.Tests
         }
 
         [Test]
+        public void TestECDHBasicAgreementCofactor()
+        {
+            SecureRandom random = new SecureRandom();
+
+            X9ECParameters x9 = CustomNamedCurves.GetByName("curve25519");
+            ECDomainParameters ec = new ECDomainParameters(x9.Curve, x9.G, x9.N, x9.H, x9.GetSeed());
+
+            ECKeyPairGenerator kpg = new ECKeyPairGenerator();
+            kpg.Init(new ECKeyGenerationParameters(ec, random));
+
+            AsymmetricCipherKeyPair p1 = kpg.GenerateKeyPair();
+            AsymmetricCipherKeyPair p2 = kpg.GenerateKeyPair();
+
+            IBasicAgreement e1 = new ECDHBasicAgreement();
+            IBasicAgreement e2 = new ECDHBasicAgreement();
+
+            e1.Init(p1.Private);
+            e2.Init(p2.Private);
+
+            BigInteger k1 = e1.CalculateAgreement(p2.Public);
+            BigInteger k2 = e2.CalculateAgreement(p1.Public);
+
+            if (!k1.Equals(k2))
+            {
+                Fail("calculated agreement test failed");
+            }
+        }
+
+        [Test]
         public void TestECMqvTestVector1()
         {
             // Test Vector from GEC-2
@@ -843,7 +869,7 @@ namespace Org.BouncyCastle.Crypto.Tests
             ECDomainParameters parameters = new ECDomainParameters(
                 curve,
                 curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                n);
+                n, BigInteger.One);
 
             ECKeyPairGenerator pGen = new ECKeyPairGenerator();
 
@@ -909,7 +935,8 @@ namespace Org.BouncyCastle.Crypto.Tests
             TestECDsa191bitBinary();
             TestECDsa239bitBinary();
             TestECDsaKeyGenTest();
-            TestECBasicAgreementTest();
+            TestECDHBasicAgreement();
+            TestECDHBasicAgreementCofactor();
 
             TestECDsaP224Sha224();
             TestECDsaP224OneByteOver();
diff --git a/crypto/test/src/crypto/test/SM2EngineTest.cs b/crypto/test/src/crypto/test/SM2EngineTest.cs
index cc9440e86..f961b0acb 100644
--- a/crypto/test/src/crypto/test/SM2EngineTest.cs
+++ b/crypto/test/src/crypto/test/SM2EngineTest.cs
@@ -28,10 +28,11 @@ namespace Org.BouncyCastle.Crypto.Tests
             BigInteger SM2_ECC_A = new BigInteger("787968B4FA32C3FD2417842E73BBFEFF2F3C848B6831D7E0EC65228B3937E498", 16);
             BigInteger SM2_ECC_B = new BigInteger("63E4C6D3B23B0C849CF84241484BFE48F61D59A5B16BA06E6E12D1DA27C5249A", 16);
             BigInteger SM2_ECC_N = new BigInteger("8542D69E4C044F18E8B92435BF6FF7DD297720630485628D5AE74EE7C32E79B7", 16);
+            BigInteger SM2_ECC_H = BigInteger.One;
             BigInteger SM2_ECC_GX = new BigInteger("421DEBD61B62EAB6746434EBC3CC315E32220B3BADD50BDC4C4E6C147FEDD43D", 16);
             BigInteger SM2_ECC_GY = new BigInteger("0680512BCBB42C07D47349D2153B70C4E5D7FDFCBFA36EA1A85841B9E46E09A2", 16);
 
-            ECCurve curve = new FpCurve(SM2_ECC_P, SM2_ECC_A, SM2_ECC_B);
+            ECCurve curve = new FpCurve(SM2_ECC_P, SM2_ECC_A, SM2_ECC_B, SM2_ECC_N, SM2_ECC_H);
 
             ECPoint g = curve.CreatePoint(SM2_ECC_GX, SM2_ECC_GY);
             ECDomainParameters domainParams = new ECDomainParameters(curve, g, SM2_ECC_N);
@@ -104,11 +105,11 @@ namespace Org.BouncyCastle.Crypto.Tests
             BigInteger SM2_ECC_A = new BigInteger("00", 16);
             BigInteger SM2_ECC_B = new BigInteger("E78BCD09746C202378A7E72B12BCE00266B9627ECB0B5A25367AD1AD4CC6242B", 16);
             BigInteger SM2_ECC_N = new BigInteger("7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFBC972CF7E6B6F900945B3C6A0CF6161D", 16);
+            BigInteger SM2_ECC_H = BigInteger.ValueOf(4);
             BigInteger SM2_ECC_GX = new BigInteger("00CDB9CA7F1E6B0441F658343F4B10297C0EF9B6491082400A62E7A7485735FADD", 16);
             BigInteger SM2_ECC_GY = new BigInteger("013DE74DA65951C4D76DC89220D5F7777A611B1C38BAE260B175951DC8060C2B3E", 16);
-            BigInteger SM2_ECC_H = BigInteger.ValueOf(4);
 
-            ECCurve curve = new F2mCurve(257, 12, SM2_ECC_A, SM2_ECC_B);
+            ECCurve curve = new F2mCurve(257, 12, SM2_ECC_A, SM2_ECC_B, SM2_ECC_N, SM2_ECC_H);
 
             ECPoint g = curve.CreatePoint(SM2_ECC_GX, SM2_ECC_GY);
             ECDomainParameters domainParams = new ECDomainParameters(curve, g, SM2_ECC_N, SM2_ECC_H);
diff --git a/crypto/test/src/crypto/test/SM2KeyExchangeTest.cs b/crypto/test/src/crypto/test/SM2KeyExchangeTest.cs
index 41993218c..6308383a6 100644
--- a/crypto/test/src/crypto/test/SM2KeyExchangeTest.cs
+++ b/crypto/test/src/crypto/test/SM2KeyExchangeTest.cs
@@ -30,10 +30,11 @@ namespace Org.BouncyCastle.Crypto.Tests
             BigInteger SM2_ECC_A = new BigInteger("787968B4FA32C3FD2417842E73BBFEFF2F3C848B6831D7E0EC65228B3937E498", 16);
             BigInteger SM2_ECC_B = new BigInteger("63E4C6D3B23B0C849CF84241484BFE48F61D59A5B16BA06E6E12D1DA27C5249A", 16);
             BigInteger SM2_ECC_N = new BigInteger("8542D69E4C044F18E8B92435BF6FF7DD297720630485628D5AE74EE7C32E79B7", 16);
+            BigInteger SM2_ECC_H = BigInteger.One;
             BigInteger SM2_ECC_GX = new BigInteger("421DEBD61B62EAB6746434EBC3CC315E32220B3BADD50BDC4C4E6C147FEDD43D", 16);
             BigInteger SM2_ECC_GY = new BigInteger("0680512BCBB42C07D47349D2153B70C4E5D7FDFCBFA36EA1A85841B9E46E09A2", 16);
 
-            ECCurve curve = new FpCurve(SM2_ECC_P, SM2_ECC_A, SM2_ECC_B);
+            ECCurve curve = new FpCurve(SM2_ECC_P, SM2_ECC_A, SM2_ECC_B, SM2_ECC_N, SM2_ECC_H);
 
             ECPoint g = curve.CreatePoint(SM2_ECC_GX, SM2_ECC_GY);
             ECDomainParameters domainParams = new ECDomainParameters(curve, g, SM2_ECC_N);
@@ -119,11 +120,11 @@ namespace Org.BouncyCastle.Crypto.Tests
             BigInteger SM2_ECC_A = new BigInteger("00", 16);
             BigInteger SM2_ECC_B = new BigInteger("E78BCD09746C202378A7E72B12BCE00266B9627ECB0B5A25367AD1AD4CC6242B", 16);
             BigInteger SM2_ECC_N = new BigInteger("7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFBC972CF7E6B6F900945B3C6A0CF6161D", 16);
+            BigInteger SM2_ECC_H = BigInteger.ValueOf(4);
             BigInteger SM2_ECC_GX = new BigInteger("00CDB9CA7F1E6B0441F658343F4B10297C0EF9B6491082400A62E7A7485735FADD", 16);
             BigInteger SM2_ECC_GY = new BigInteger("013DE74DA65951C4D76DC89220D5F7777A611B1C38BAE260B175951DC8060C2B3E", 16);
-            BigInteger SM2_ECC_H = BigInteger.ValueOf(4);
 
-            ECCurve curve = new F2mCurve(257, 12, SM2_ECC_A, SM2_ECC_B);
+            ECCurve curve = new F2mCurve(257, 12, SM2_ECC_A, SM2_ECC_B, SM2_ECC_N, SM2_ECC_H);
 
             ECPoint g = curve.CreatePoint(SM2_ECC_GX, SM2_ECC_GY);
             ECDomainParameters domainParams = new ECDomainParameters(curve, g, SM2_ECC_N, SM2_ECC_H);
diff --git a/crypto/test/src/crypto/test/SM2SignerTest.cs b/crypto/test/src/crypto/test/SM2SignerTest.cs
index 795fb6323..a9e6c48e5 100644
--- a/crypto/test/src/crypto/test/SM2SignerTest.cs
+++ b/crypto/test/src/crypto/test/SM2SignerTest.cs
@@ -29,10 +29,11 @@ namespace Org.BouncyCastle.Crypto.Tests
             BigInteger SM2_ECC_A = new BigInteger("787968B4FA32C3FD2417842E73BBFEFF2F3C848B6831D7E0EC65228B3937E498", 16);
             BigInteger SM2_ECC_B = new BigInteger("63E4C6D3B23B0C849CF84241484BFE48F61D59A5B16BA06E6E12D1DA27C5249A", 16);
             BigInteger SM2_ECC_N = new BigInteger("8542D69E4C044F18E8B92435BF6FF7DD297720630485628D5AE74EE7C32E79B7", 16);
+            BigInteger SM2_ECC_H = BigInteger.ValueOf(4);
             BigInteger SM2_ECC_GX = new BigInteger("421DEBD61B62EAB6746434EBC3CC315E32220B3BADD50BDC4C4E6C147FEDD43D", 16);
             BigInteger SM2_ECC_GY = new BigInteger("0680512BCBB42C07D47349D2153B70C4E5D7FDFCBFA36EA1A85841B9E46E09A2", 16);
 
-            ECCurve curve = new FpCurve(SM2_ECC_P, SM2_ECC_A, SM2_ECC_B);
+            ECCurve curve = new FpCurve(SM2_ECC_P, SM2_ECC_A, SM2_ECC_B, SM2_ECC_N, SM2_ECC_H);
 
             ECPoint g = curve.CreatePoint(SM2_ECC_GX, SM2_ECC_GY);
             ECDomainParameters domainParams = new ECDomainParameters(curve, g, SM2_ECC_N);
@@ -76,10 +77,11 @@ namespace Org.BouncyCastle.Crypto.Tests
             BigInteger SM2_ECC_A = new BigInteger("00", 16);
             BigInteger SM2_ECC_B = new BigInteger("E78BCD09746C202378A7E72B12BCE00266B9627ECB0B5A25367AD1AD4CC6242B", 16);
             BigInteger SM2_ECC_N = new BigInteger("7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFBC972CF7E6B6F900945B3C6A0CF6161D", 16);
+            BigInteger SM2_ECC_H = BigInteger.ValueOf(4);
             BigInteger SM2_ECC_GX = new BigInteger("00CDB9CA7F1E6B0441F658343F4B10297C0EF9B6491082400A62E7A7485735FADD", 16);
             BigInteger SM2_ECC_GY = new BigInteger("013DE74DA65951C4D76DC89220D5F7777A611B1C38BAE260B175951DC8060C2B3E", 16);
 
-            ECCurve curve = new F2mCurve(257, 12, SM2_ECC_A, SM2_ECC_B);
+            ECCurve curve = new F2mCurve(257, 12, SM2_ECC_A, SM2_ECC_B, SM2_ECC_N, SM2_ECC_H);
 
             ECPoint g = curve.CreatePoint(SM2_ECC_GX, SM2_ECC_GY);
             ECDomainParameters domainParams = new ECDomainParameters(curve, g, SM2_ECC_N);
diff --git a/crypto/test/src/math/ec/rfc8032/test/Ed25519Test.cs b/crypto/test/src/math/ec/rfc8032/test/Ed25519Test.cs
new file mode 100644
index 000000000..43ea23988
--- /dev/null
+++ b/crypto/test/src/math/ec/rfc8032/test/Ed25519Test.cs
@@ -0,0 +1,231 @@
+using System;
+
+using NUnit.Framework;
+
+using Org.BouncyCastle.Security;
+using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Utilities.Encoders;
+
+namespace Org.BouncyCastle.Math.EC.Rfc8032.Tests
+{
+    [TestFixture]
+    public class Ed25519Test
+    {
+		private static readonly SecureRandom Random = new SecureRandom();
+      
+		[SetUp]
+        public void SetUp()
+        {
+            Ed25519.Precompute();
+        }
+
+		[Test]
+        public void TestEd25519Consistency()
+        {
+            byte[] sk = new byte[Ed25519.SecretKeySize];
+            byte[] pk = new byte[Ed25519.PublicKeySize];
+            byte[] m = new byte[255];
+            byte[] sig1 = new byte[Ed25519.SignatureSize];
+			byte[] sig2 = new byte[Ed25519.SignatureSize];
+
+			Random.NextBytes(m);
+
+            for (int i = 0; i < 10; ++i)
+            {
+				Random.NextBytes(sk);
+                Ed25519.GeneratePublicKey(sk, 0, pk, 0);
+
+                int mLen = Random.Next() & 255;
+
+                Ed25519.Sign(sk, 0, m, 0, mLen, sig1, 0);
+                Ed25519.Sign(sk, 0, pk, 0, m, 0, mLen, sig2, 0);
+
+                Assert.IsTrue(Arrays.AreEqual(sig1, sig2), "Consistent signatures #" + i);
+
+                bool shouldVerify = Ed25519.Verify(sig1, 0, pk, 0, m, 0, mLen);
+
+                Assert.IsTrue(shouldVerify, "Consistent sign/verify #" + i);
+
+                sig1[Ed25519.PublicKeySize - 1] ^= 0x80;
+                bool shouldNotVerify = Ed25519.Verify(sig1, 0, pk, 0, m, 0, mLen);
+
+                Assert.IsFalse(shouldNotVerify, "Consistent verification failure #" + i);
+            }
+        }
+
+        [Test]
+		public void TestEd25519Vector1()
+        {
+            CheckEd25519Vector(
+                ("9d61b19deffd5a60ba844af492ec2cc4"
+                + "4449c5697b326919703bac031cae7f60"),
+                ("d75a980182b10ab7d54bfed3c964073a"
+                + "0ee172f3daa62325af021a68f707511a"),
+                "",
+                ("e5564300c360ac729086e2cc806e828a"
+                + "84877f1eb8e5d974d873e06522490155"
+                + "5fb8821590a33bacc61e39701cf9b46b"
+                + "d25bf5f0595bbe24655141438e7a100b"),
+                "Ed25519 Vector #1");
+        }
+      
+		[Test]
+        public void TestEd25519Vector2()
+        {
+            CheckEd25519Vector(
+                ("4ccd089b28ff96da9db6c346ec114e0f"
+                + "5b8a319f35aba624da8cf6ed4fb8a6fb"),
+                ("3d4017c3e843895a92b70aa74d1b7ebc"
+                + "9c982ccf2ec4968cc0cd55f12af4660c"),
+                "72",
+                ("92a009a9f0d4cab8720e820b5f642540"
+                + "a2b27b5416503f8fb3762223ebdb69da"
+                + "085ac1e43e15996e458f3613d0f11d8c"
+                + "387b2eaeb4302aeeb00d291612bb0c00"),
+                "Ed25519 Vector #2");
+        }
+      
+		[Test]
+        public void TestEd25519Vector3()
+        {
+            CheckEd25519Vector(
+                ("c5aa8df43f9f837bedb7442f31dcb7b1"
+                + "66d38535076f094b85ce3a2e0b4458f7"),
+                ("fc51cd8e6218a1a38da47ed00230f058"
+                + "0816ed13ba3303ac5deb911548908025"),
+                "af82",
+                ("6291d657deec24024827e69c3abe01a3"
+                + "0ce548a284743a445e3680d7db5ac3ac"
+                + "18ff9b538d16f290ae67f760984dc659"
+                + "4a7c15e9716ed28dc027beceea1ec40a"),
+                "Ed25519 Vector #3");
+        }
+
+        [Test]
+        public void TestEd25519Vector1023()
+        {
+            string m =
+                "08b8b2b733424243760fe426a4b54908" +
+                "632110a66c2f6591eabd3345e3e4eb98" +
+                "fa6e264bf09efe12ee50f8f54e9f77b1" +
+                "e355f6c50544e23fb1433ddf73be84d8" +
+                "79de7c0046dc4996d9e773f4bc9efe57" +
+                "38829adb26c81b37c93a1b270b20329d" +
+                "658675fc6ea534e0810a4432826bf58c" +
+                "941efb65d57a338bbd2e26640f89ffbc" +
+                "1a858efcb8550ee3a5e1998bd177e93a" +
+                "7363c344fe6b199ee5d02e82d522c4fe" +
+                "ba15452f80288a821a579116ec6dad2b" +
+                "3b310da903401aa62100ab5d1a36553e" +
+                "06203b33890cc9b832f79ef80560ccb9" +
+                "a39ce767967ed628c6ad573cb116dbef" +
+                "efd75499da96bd68a8a97b928a8bbc10" +
+                "3b6621fcde2beca1231d206be6cd9ec7" +
+                "aff6f6c94fcd7204ed3455c68c83f4a4" +
+                "1da4af2b74ef5c53f1d8ac70bdcb7ed1" +
+                "85ce81bd84359d44254d95629e9855a9" +
+                "4a7c1958d1f8ada5d0532ed8a5aa3fb2" +
+                "d17ba70eb6248e594e1a2297acbbb39d" +
+                "502f1a8c6eb6f1ce22b3de1a1f40cc24" +
+                "554119a831a9aad6079cad88425de6bd" +
+                "e1a9187ebb6092cf67bf2b13fd65f270" +
+                "88d78b7e883c8759d2c4f5c65adb7553" +
+                "878ad575f9fad878e80a0c9ba63bcbcc" +
+                "2732e69485bbc9c90bfbd62481d9089b" +
+                "eccf80cfe2df16a2cf65bd92dd597b07" +
+                "07e0917af48bbb75fed413d238f5555a" +
+                "7a569d80c3414a8d0859dc65a46128ba" +
+                "b27af87a71314f318c782b23ebfe808b" +
+                "82b0ce26401d2e22f04d83d1255dc51a" +
+                "ddd3b75a2b1ae0784504df543af8969b" +
+                "e3ea7082ff7fc9888c144da2af58429e" +
+                "c96031dbcad3dad9af0dcbaaaf268cb8" +
+                "fcffead94f3c7ca495e056a9b47acdb7" +
+                "51fb73e666c6c655ade8297297d07ad1" +
+                "ba5e43f1bca32301651339e22904cc8c" +
+                "42f58c30c04aafdb038dda0847dd988d" +
+                "cda6f3bfd15c4b4c4525004aa06eeff8" +
+                "ca61783aacec57fb3d1f92b0fe2fd1a8" +
+                "5f6724517b65e614ad6808d6f6ee34df" +
+                "f7310fdc82aebfd904b01e1dc54b2927" +
+                "094b2db68d6f903b68401adebf5a7e08" +
+                "d78ff4ef5d63653a65040cf9bfd4aca7" +
+                "984a74d37145986780fc0b16ac451649" +
+                "de6188a7dbdf191f64b5fc5e2ab47b57" +
+                "f7f7276cd419c17a3ca8e1b939ae49e4" +
+                "88acba6b965610b5480109c8b17b80e1" +
+                "b7b750dfc7598d5d5011fd2dcc5600a3" +
+                "2ef5b52a1ecc820e308aa342721aac09" +
+                "43bf6686b64b2579376504ccc493d97e" +
+                "6aed3fb0f9cd71a43dd497f01f17c0e2" +
+                "cb3797aa2a2f256656168e6c496afc5f" +
+                "b93246f6b1116398a346f1a641f3b041" +
+                "e989f7914f90cc2c7fff357876e506b5" +
+                "0d334ba77c225bc307ba537152f3f161" +
+                "0e4eafe595f6d9d90d11faa933a15ef1" +
+                "369546868a7f3a45a96768d40fd9d034" +
+                "12c091c6315cf4fde7cb68606937380d" +
+                "b2eaaa707b4c4185c32eddcdd306705e" +
+                "4dc1ffc872eeee475a64dfac86aba41c" +
+                "0618983f8741c5ef68d3a101e8a3b8ca" +
+                "c60c905c15fc910840b94c00a0b9d0";
+
+            CheckEd25519Vector(
+                ("f5e5767cf153319517630f226876b86c"
+                + "8160cc583bc013744c6bf255f5cc0ee5"),
+                ("278117fc144c72340f67d0f2316e8386"
+                + "ceffbf2b2428c9c51fef7c597f1d426e"),
+                m,
+                ("0aab4c900501b3e24d7cdf4663326a3a"
+                + "87df5e4843b2cbdb67cbf6e460fec350"
+                + "aa5371b1508f9f4528ecea23c436d94b"
+                + "5e8fcd4f681e30a6ac00a9704a188a03"),
+                "Ed25519 Vector #1023");
+        }
+
+        [Test]
+        public void TestEd25519VectorSHAabc()
+        {
+            CheckEd25519Vector(
+                ("833fe62409237b9d62ec77587520911e"
+                + "9a759cec1d19755b7da901b96dca3d42"),
+                ("ec172b93ad5e563bf4932c70e1245034"
+                + "c35467ef2efd4d64ebf819683467e2bf"),
+                ("ddaf35a193617abacc417349ae204131"
+                + "12e6fa4e89a97ea20a9eeee64b55d39a"
+                + "2192992a274fc1a836ba3c23a3feebbd"
+                + "454d4423643ce80e2a9ac94fa54ca49f"),
+                ("dc2a4459e7369633a52b1bf277839a00"
+                + "201009a3efbf3ecb69bea2186c26b589"
+                + "09351fc9ac90b3ecfdfbc7c66431e030"
+                + "3dca179c138ac17ad9bef1177331a704"),
+                "Ed25519 Vector SHA(abc)");
+        }
+      
+        private static void CheckEd25519Vector(string sSK, string sPK, string sM, string sSig, string text)
+        {
+            byte[] sk = Hex.Decode(sSK);
+
+            byte[] pk = Hex.Decode(sPK);
+            byte[] pkGen = new byte[Ed25519.PublicKeySize];
+            Ed25519.GeneratePublicKey(sk, 0, pkGen, 0);
+            Assert.IsTrue(Arrays.AreEqual(pk, pkGen), text);
+         
+			byte[] m = Hex.Decode(sM);
+            byte[] sig = Hex.Decode(sSig);
+            byte[] sigGen = new byte[Ed25519.SignatureSize];
+            Ed25519.Sign(sk, 0, m, 0, m.Length, sigGen, 0);
+            Assert.IsTrue(Arrays.AreEqual(sig, sigGen), text);
+
+            Ed25519.Sign(sk, 0, pk, 0, m, 0, m.Length, sigGen, 0);
+            Assert.IsTrue(Arrays.AreEqual(sig, sigGen), text);
+
+            bool shouldVerify = Ed25519.Verify(sig, 0, pk, 0, m, 0, m.Length);
+            Assert.IsTrue(shouldVerify, text);
+
+			sig[Ed25519.SignatureSize - 1] ^= 0x80;
+            bool shouldNotVerify = Ed25519.Verify(sig, 0, pk, 0, m, 0, m.Length);
+            Assert.IsFalse(shouldNotVerify, text);
+        }
+    }
+}
diff --git a/crypto/test/src/math/ec/rfc8032/test/Ed448Test.cs b/crypto/test/src/math/ec/rfc8032/test/Ed448Test.cs
new file mode 100644
index 000000000..98c487c09
--- /dev/null
+++ b/crypto/test/src/math/ec/rfc8032/test/Ed448Test.cs
@@ -0,0 +1,400 @@
+using System;
+
+using NUnit.Framework;
+
+using Org.BouncyCastle.Security;
+using Org.BouncyCastle.Utilities;
+using Org.BouncyCastle.Utilities.Encoders;
+
+namespace Org.BouncyCastle.Math.EC.Rfc8032.Tests
+{
+    [TestFixture]
+    public class Ed448Test
+    {
+        private static readonly SecureRandom Random = new SecureRandom();
+
+        [SetUp]
+        public void SetUp()
+        {
+            Ed448.Precompute();
+        }
+
+        [Test]
+        public void TestEd448Consistency()
+        {
+            byte[] sk = new byte[Ed448.SecretKeySize];
+            byte[] pk = new byte[Ed448.PublicKeySize];
+            byte[] ctx = new byte[Random.Next() & 7];
+            byte[] m = new byte[255];
+            byte[] sig1 = new byte[Ed448.SignatureSize];
+            byte[] sig2 = new byte[Ed448.SignatureSize];
+
+            Random.NextBytes(ctx);
+            Random.NextBytes(m);
+
+            for (int i = 0; i < 10; ++i)
+            {
+                Random.NextBytes(sk);
+                Ed448.GeneratePublicKey(sk, 0, pk, 0);
+
+                int mLen = Random.Next() & 255;
+
+                Ed448.Sign(sk, 0, ctx, m, 0, mLen, sig1, 0);
+                Ed448.Sign(sk, 0, pk, 0, ctx, m, 0, mLen, sig2, 0);
+
+                Assert.IsTrue(Arrays.AreEqual(sig1, sig2), "Consistent signatures #" + i);
+
+                bool shouldVerify = Ed448.Verify(sig1, 0, pk, 0, ctx, m, 0, mLen);
+
+                Assert.IsTrue(shouldVerify, "Consistent sign/verify #" + i);
+
+                sig1[Ed448.PublicKeySize - 1] ^= 0x80;
+                bool shouldNotVerify = Ed448.Verify(sig1, 0, pk, 0, ctx, m, 0, mLen);
+
+                Assert.IsFalse(shouldNotVerify, "Consistent verification failure #" + i);
+            }
+        }
+
+        [Test]
+        public void TestEd448Vector1()
+        {
+            CheckEd448Vector(
+                ( "6c82a562cb808d10d632be89c8513ebf"
+                + "6c929f34ddfa8c9f63c9960ef6e348a3"
+                + "528c8a3fcc2f044e39a3fc5b94492f8f"
+                + "032e7549a20098f95b"),
+                ( "5fd7449b59b461fd2ce787ec616ad46a"
+                + "1da1342485a70e1f8a0ea75d80e96778"
+                + "edf124769b46c7061bd6783df1e50f6c"
+                + "d1fa1abeafe8256180"),
+                "",
+                "",
+                ( "533a37f6bbe457251f023c0d88f976ae"
+                + "2dfb504a843e34d2074fd823d41a591f"
+                + "2b233f034f628281f2fd7a22ddd47d78"
+                + "28c59bd0a21bfd3980ff0d2028d4b18a"
+                + "9df63e006c5d1c2d345b925d8dc00b41"
+                + "04852db99ac5c7cdda8530a113a0f4db"
+                + "b61149f05a7363268c71d95808ff2e65"
+                + "2600"),
+                "Ed448 Vector #1");
+        }
+
+        [Test]
+        public void TestEd448Vector2()
+        {
+            CheckEd448Vector(
+                ( "c4eab05d357007c632f3dbb48489924d"
+                + "552b08fe0c353a0d4a1f00acda2c463a"
+                + "fbea67c5e8d2877c5e3bc397a659949e"
+                + "f8021e954e0a12274e"),
+                ( "43ba28f430cdff456ae531545f7ecd0a"
+                + "c834a55d9358c0372bfa0c6c6798c086"
+                + "6aea01eb00742802b8438ea4cb82169c"
+                + "235160627b4c3a9480"),
+                "03",
+                "",
+                ( "26b8f91727bd62897af15e41eb43c377"
+                + "efb9c610d48f2335cb0bd0087810f435"
+                + "2541b143c4b981b7e18f62de8ccdf633"
+                + "fc1bf037ab7cd779805e0dbcc0aae1cb"
+                + "cee1afb2e027df36bc04dcecbf154336"
+                + "c19f0af7e0a6472905e799f1953d2a0f"
+                + "f3348ab21aa4adafd1d234441cf807c0"
+                + "3a00"),
+                "Ed448 Vector #2");
+        }
+
+        [Test]
+        public void TestEd448Vector3()
+        {
+            CheckEd448Vector(
+                ( "c4eab05d357007c632f3dbb48489924d"
+                + "552b08fe0c353a0d4a1f00acda2c463a"
+                + "fbea67c5e8d2877c5e3bc397a659949e"
+                + "f8021e954e0a12274e"),
+                ( "43ba28f430cdff456ae531545f7ecd0a"
+                + "c834a55d9358c0372bfa0c6c6798c086"
+                + "6aea01eb00742802b8438ea4cb82169c"
+                + "235160627b4c3a9480"),
+                "03",
+                "666f6f",
+                ( "d4f8f6131770dd46f40867d6fd5d5055"
+                + "de43541f8c5e35abbcd001b32a89f7d2"
+                + "151f7647f11d8ca2ae279fb842d60721"
+                + "7fce6e042f6815ea000c85741de5c8da"
+                + "1144a6a1aba7f96de42505d7a7298524"
+                + "fda538fccbbb754f578c1cad10d54d0d"
+                + "5428407e85dcbc98a49155c13764e66c"
+                + "3c00"),
+                "Ed448 Vector #3");
+        }
+
+        [Test]
+        public void TestEd448Vector4()
+        {
+            CheckEd448Vector(
+                ( "cd23d24f714274e744343237b93290f5"
+                + "11f6425f98e64459ff203e8985083ffd"
+                + "f60500553abc0e05cd02184bdb89c4cc"
+                + "d67e187951267eb328"),
+                ( "dcea9e78f35a1bf3499a831b10b86c90"
+                + "aac01cd84b67a0109b55a36e9328b1e3"
+                + "65fce161d71ce7131a543ea4cb5f7e9f"
+                + "1d8b00696447001400"),
+                "0c3e544074ec63b0265e0c",
+                "",
+                ( "1f0a8888ce25e8d458a21130879b840a"
+                + "9089d999aaba039eaf3e3afa090a09d3"
+                + "89dba82c4ff2ae8ac5cdfb7c55e94d5d"
+                + "961a29fe0109941e00b8dbdeea6d3b05"
+                + "1068df7254c0cdc129cbe62db2dc957d"
+                + "bb47b51fd3f213fb8698f064774250a5"
+                + "028961c9bf8ffd973fe5d5c206492b14"
+                + "0e00"),
+                "Ed448 Vector #4");
+        }
+
+        [Test]
+        public void TestEd448Vector5()
+        {
+            CheckEd448Vector(
+                ( "258cdd4ada32ed9c9ff54e63756ae582"
+                + "fb8fab2ac721f2c8e676a72768513d93"
+                + "9f63dddb55609133f29adf86ec9929dc"
+                + "cb52c1c5fd2ff7e21b"),
+                ( "3ba16da0c6f2cc1f30187740756f5e79"
+                + "8d6bc5fc015d7c63cc9510ee3fd44adc"
+                + "24d8e968b6e46e6f94d19b945361726b"
+                + "d75e149ef09817f580"),
+                "64a65f3cdedcdd66811e2915",
+                "",
+                ( "7eeeab7c4e50fb799b418ee5e3197ff6"
+                + "bf15d43a14c34389b59dd1a7b1b85b4a"
+                + "e90438aca634bea45e3a2695f1270f07"
+                + "fdcdf7c62b8efeaf00b45c2c96ba457e"
+                + "b1a8bf075a3db28e5c24f6b923ed4ad7"
+                + "47c3c9e03c7079efb87cb110d3a99861"
+                + "e72003cbae6d6b8b827e4e6c143064ff"
+                + "3c00"),
+                "Ed448 Vector #5");
+        }
+
+        [Test]
+        public void TestEd448Vector6()
+        {
+            CheckEd448Vector(
+                ( "7ef4e84544236752fbb56b8f31a23a10"
+                + "e42814f5f55ca037cdcc11c64c9a3b29"
+                + "49c1bb60700314611732a6c2fea98eeb"
+                + "c0266a11a93970100e"),
+                ( "b3da079b0aa493a5772029f0467baebe"
+                + "e5a8112d9d3a22532361da294f7bb381"
+                + "5c5dc59e176b4d9f381ca0938e13c6c0"
+                + "7b174be65dfa578e80"),
+                "64a65f3cdedcdd66811e2915e7",
+                "",
+                ( "6a12066f55331b6c22acd5d5bfc5d712"
+                + "28fbda80ae8dec26bdd306743c5027cb"
+                + "4890810c162c027468675ecf645a8317"
+                + "6c0d7323a2ccde2d80efe5a1268e8aca"
+                + "1d6fbc194d3f77c44986eb4ab4177919"
+                + "ad8bec33eb47bbb5fc6e28196fd1caf5"
+                + "6b4e7e0ba5519234d047155ac727a105"
+                + "3100"),
+                "Ed448 Vector #6");
+        }
+
+        [Test]
+        public void TestEd448Vector64()
+        {
+            string m =
+                "bd0f6a3747cd561bdddf4640a332461a" +
+                "4a30a12a434cd0bf40d766d9c6d458e5" +
+                "512204a30c17d1f50b5079631f64eb31" +
+                "12182da3005835461113718d1a5ef944";
+
+            CheckEd448Vector(
+                ( "d65df341ad13e008567688baedda8e9d"
+                + "cdc17dc024974ea5b4227b6530e339bf"
+                + "f21f99e68ca6968f3cca6dfe0fb9f4fa"
+                + "b4fa135d5542ea3f01"),
+                ( "df9705f58edbab802c7f8363cfe5560a"
+                + "b1c6132c20a9f1dd163483a26f8ac53a"
+                + "39d6808bf4a1dfbd261b099bb03b3fb5"
+                + "0906cb28bd8a081f00"),
+                m,
+                "",
+                ( "554bc2480860b49eab8532d2a533b7d5"
+                + "78ef473eeb58c98bb2d0e1ce488a98b1"
+                + "8dfde9b9b90775e67f47d4a1c3482058"
+                + "efc9f40d2ca033a0801b63d45b3b722e"
+                + "f552bad3b4ccb667da350192b61c508c"
+                + "f7b6b5adadc2c8d9a446ef003fb05cba"
+                + "5f30e88e36ec2703b349ca229c267083"
+                + "3900"),
+                "Ed448 Vector #64");
+        }
+
+        [Test]
+        public void TestEd448Vector256()
+        {
+            string m =
+                "15777532b0bdd0d1389f636c5f6b9ba7" +
+                "34c90af572877e2d272dd078aa1e567c" +
+                "fa80e12928bb542330e8409f31745041" +
+                "07ecd5efac61ae7504dabe2a602ede89" +
+                "e5cca6257a7c77e27a702b3ae39fc769" +
+                "fc54f2395ae6a1178cab4738e543072f" +
+                "c1c177fe71e92e25bf03e4ecb72f47b6" +
+                "4d0465aaea4c7fad372536c8ba516a60" +
+                "39c3c2a39f0e4d832be432dfa9a706a6" +
+                "e5c7e19f397964ca4258002f7c0541b5" +
+                "90316dbc5622b6b2a6fe7a4abffd9610" +
+                "5eca76ea7b98816af0748c10df048ce0" +
+                "12d901015a51f189f3888145c03650aa" +
+                "23ce894c3bd889e030d565071c59f409" +
+                "a9981b51878fd6fc110624dcbcde0bf7" +
+                "a69ccce38fabdf86f3bef6044819de11";
+
+            CheckEd448Vector(
+                ( "2ec5fe3c17045abdb136a5e6a913e32a"
+                + "b75ae68b53d2fc149b77e504132d3756"
+                + "9b7e766ba74a19bd6162343a21c8590a"
+                + "a9cebca9014c636df5"),
+                ( "79756f014dcfe2079f5dd9e718be4171"
+                + "e2ef2486a08f25186f6bff43a9936b9b"
+                + "fe12402b08ae65798a3d81e22e9ec80e"
+                + "7690862ef3d4ed3a00"),
+                m,
+                "",
+                ( "c650ddbb0601c19ca11439e1640dd931"
+                + "f43c518ea5bea70d3dcde5f4191fe53f"
+                + "00cf966546b72bcc7d58be2b9badef28"
+                + "743954e3a44a23f880e8d4f1cfce2d7a"
+                + "61452d26da05896f0a50da66a239a8a1"
+                + "88b6d825b3305ad77b73fbac0836ecc6"
+                + "0987fd08527c1a8e80d5823e65cafe2a"
+                + "3d00"),
+                "Ed448 Vector #256");
+        }
+
+        [Test]
+        public void TestEd448Vector1023()
+        {
+            string m =
+                "6ddf802e1aae4986935f7f981ba3f035" +
+                "1d6273c0a0c22c9c0e8339168e675412" +
+                "a3debfaf435ed651558007db4384b650" +
+                "fcc07e3b586a27a4f7a00ac8a6fec2cd" +
+                "86ae4bf1570c41e6a40c931db27b2faa" +
+                "15a8cedd52cff7362c4e6e23daec0fbc" +
+                "3a79b6806e316efcc7b68119bf46bc76" +
+                "a26067a53f296dafdbdc11c77f7777e9" +
+                "72660cf4b6a9b369a6665f02e0cc9b6e" +
+                "dfad136b4fabe723d2813db3136cfde9" +
+                "b6d044322fee2947952e031b73ab5c60" +
+                "3349b307bdc27bc6cb8b8bbd7bd32321" +
+                "9b8033a581b59eadebb09b3c4f3d2277" +
+                "d4f0343624acc817804728b25ab79717" +
+                "2b4c5c21a22f9c7839d64300232eb66e" +
+                "53f31c723fa37fe387c7d3e50bdf9813" +
+                "a30e5bb12cf4cd930c40cfb4e1fc6225" +
+                "92a49588794494d56d24ea4b40c89fc0" +
+                "596cc9ebb961c8cb10adde976a5d602b" +
+                "1c3f85b9b9a001ed3c6a4d3b1437f520" +
+                "96cd1956d042a597d561a596ecd3d173" +
+                "5a8d570ea0ec27225a2c4aaff26306d1" +
+                "526c1af3ca6d9cf5a2c98f47e1c46db9" +
+                "a33234cfd4d81f2c98538a09ebe76998" +
+                "d0d8fd25997c7d255c6d66ece6fa56f1" +
+                "1144950f027795e653008f4bd7ca2dee" +
+                "85d8e90f3dc315130ce2a00375a318c7" +
+                "c3d97be2c8ce5b6db41a6254ff264fa6" +
+                "155baee3b0773c0f497c573f19bb4f42" +
+                "40281f0b1f4f7be857a4e59d416c06b4" +
+                "c50fa09e1810ddc6b1467baeac5a3668" +
+                "d11b6ecaa901440016f389f80acc4db9" +
+                "77025e7f5924388c7e340a732e554440" +
+                "e76570f8dd71b7d640b3450d1fd5f041" +
+                "0a18f9a3494f707c717b79b4bf75c984" +
+                "00b096b21653b5d217cf3565c9597456" +
+                "f70703497a078763829bc01bb1cbc8fa" +
+                "04eadc9a6e3f6699587a9e75c94e5bab" +
+                "0036e0b2e711392cff0047d0d6b05bd2" +
+                "a588bc109718954259f1d86678a579a3" +
+                "120f19cfb2963f177aeb70f2d4844826" +
+                "262e51b80271272068ef5b3856fa8535" +
+                "aa2a88b2d41f2a0e2fda7624c2850272" +
+                "ac4a2f561f8f2f7a318bfd5caf969614" +
+                "9e4ac824ad3460538fdc25421beec2cc" +
+                "6818162d06bbed0c40a387192349db67" +
+                "a118bada6cd5ab0140ee273204f628aa" +
+                "d1c135f770279a651e24d8c14d75a605" +
+                "9d76b96a6fd857def5e0b354b27ab937" +
+                "a5815d16b5fae407ff18222c6d1ed263" +
+                "be68c95f32d908bd895cd76207ae7264" +
+                "87567f9a67dad79abec316f683b17f2d" +
+                "02bf07e0ac8b5bc6162cf94697b3c27c" +
+                "d1fea49b27f23ba2901871962506520c" +
+                "392da8b6ad0d99f7013fbc06c2c17a56" +
+                "9500c8a7696481c1cd33e9b14e40b82e" +
+                "79a5f5db82571ba97bae3ad3e0479515" +
+                "bb0e2b0f3bfcd1fd33034efc6245eddd" +
+                "7ee2086ddae2600d8ca73e214e8c2b0b" +
+                "db2b047c6a464a562ed77b73d2d841c4" +
+                "b34973551257713b753632efba348169" +
+                "abc90a68f42611a40126d7cb21b58695" +
+                "568186f7e569d2ff0f9e745d0487dd2e" +
+                "b997cafc5abf9dd102e62ff66cba87";
+
+            CheckEd448Vector(
+                ( "872d093780f5d3730df7c212664b37b8"
+                + "a0f24f56810daa8382cd4fa3f77634ec"
+                + "44dc54f1c2ed9bea86fafb7632d8be19"
+                + "9ea165f5ad55dd9ce8"),
+                ( "a81b2e8a70a5ac94ffdbcc9badfc3feb"
+                + "0801f258578bb114ad44ece1ec0e799d"
+                + "a08effb81c5d685c0c56f64eecaef8cd"
+                + "f11cc38737838cf400"),
+                m,
+                "",
+                ( "e301345a41a39a4d72fff8df69c98075"
+                + "a0cc082b802fc9b2b6bc503f926b65bd"
+                + "df7f4c8f1cb49f6396afc8a70abe6d8a"
+                + "ef0db478d4c6b2970076c6a0484fe76d"
+                + "76b3a97625d79f1ce240e7c576750d29"
+                + "5528286f719b413de9ada3e8eb78ed57"
+                + "3603ce30d8bb761785dc30dbc320869e"
+                + "1a00"),
+                "Ed448 Vector #1023");
+        }
+
+        private static void CheckEd448Vector(string sSK, string sPK, string sM, string sCTX, string sSig, string text)
+        {
+            byte[] sk = Hex.Decode(sSK);
+
+            byte[] pk = Hex.Decode(sPK);
+            byte[] pkGen = new byte[Ed448.PublicKeySize];
+            Ed448.GeneratePublicKey(sk, 0, pkGen, 0);
+            Assert.IsTrue(Arrays.AreEqual(pk, pkGen), text);
+
+            byte[] m = Hex.Decode(sM);
+            byte[] ctx = Hex.Decode(sCTX);
+            byte[] sig = Hex.Decode(sSig);
+            byte[] sigGen = new byte[Ed448.SignatureSize];
+            Ed448.Sign(sk, 0, ctx, m, 0, m.Length, sigGen, 0);
+            Assert.IsTrue(Arrays.AreEqual(sig, sigGen), text);
+
+            Ed448.Sign(sk, 0, pk, 0, ctx, m, 0, m.Length, sigGen, 0);
+            Assert.IsTrue(Arrays.AreEqual(sig, sigGen), text);
+
+            bool shouldVerify = Ed448.Verify(sig, 0, pk, 0, ctx, m, 0, m.Length);
+            Assert.IsTrue(shouldVerify, text);
+
+            sig[Ed448.SignatureSize - 1] ^= 0x80;
+            bool shouldNotVerify = Ed448.Verify(sig, 0, pk, 0, ctx, m, 0, m.Length);
+            Assert.IsFalse(shouldNotVerify, text);
+        }
+    }
+}
diff --git a/crypto/test/src/math/ec/test/ECPointTest.cs b/crypto/test/src/math/ec/test/ECPointTest.cs
index 089fb88b3..a5ca083e2 100644
--- a/crypto/test/src/math/ec/test/ECPointTest.cs
+++ b/crypto/test/src/math/ec/test/ECPointTest.cs
@@ -442,6 +442,22 @@ namespace Org.BouncyCastle.Math.EC.Tests
             }
         }
 
+        private void ImplValidityTest(ECCurve c, ECPoint g)
+        {
+            Assert.IsTrue(g.IsValid());
+
+            BigInteger h = c.Cofactor;
+            if (h != null && h.CompareTo(BigInteger.One) > 0)
+            {
+                if (ECAlgorithms.IsF2mCurve(c))
+                {
+                    ECPoint order2 = c.CreatePoint(BigInteger.Zero, c.B.Sqrt().ToBigInteger());
+                    ECPoint bad = g.Add(order2);
+                    Assert.IsFalse(bad.IsValid());
+                }
+            }
+        }
+
         private void ImplAddSubtractMultiplyTwiceEncodingTestAllCoords(X9ECParameters x9ECParameters)
         {
             BigInteger n = x9ECParameters.N;
@@ -470,6 +486,8 @@ namespace Org.BouncyCastle.Math.EC.Tests
                     ImplAddSubtractMultiplyTwiceEncodingTest(c, q, n);
 
                     ImplSqrtTest(c);
+
+                    ImplValidityTest(c, g);
                 }
             }
         }
diff --git a/crypto/test/src/security/test/TestEncodings.cs b/crypto/test/src/security/test/TestEncodings.cs
index 557d2dc51..a70d5b5b7 100644
--- a/crypto/test/src/security/test/TestEncodings.cs
+++ b/crypto/test/src/security/test/TestEncodings.cs
@@ -32,24 +32,19 @@ namespace Org.BouncyCastle.Security.Tests
 			BigInteger ECPubQY = new BigInteger(Base64.Decode("JrlJfxu3WGhqwtL/55BOs/wsUeiDFsvXcGhB8DGx"));
 			BigInteger ECPrivD = new BigInteger(Base64.Decode("GYQmd/NF1B+He1iMkWt3by2Az6Eu07t0ynJ4YCAo"));
 
-			FpCurve curve = new FpCurve(
-				new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
-				new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-				new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
-
-			ECDomainParameters ecDomain =
-				new ECDomainParameters(
-					curve,
-					new FpPoint(curve,
-						curve.FromBigInteger(ECParraGX),
-						curve.FromBigInteger(ECParraGY)),
-				ECParraN);
-
-			ECPublicKeyParameters ecPub = new ECPublicKeyParameters(
-				new FpPoint(
-					curve,
-					curve.FromBigInteger(ECPubQX),
-					curve.FromBigInteger(ECPubQY)),
+            FpCurve curve = new FpCurve(
+                new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
+                new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
+                new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16), // b
+                ECParraN, ECParraH);
+
+			ECDomainParameters ecDomain = new ECDomainParameters(
+				curve,
+                curve.ValidatePoint(ECParraGX, ECParraGY),
+                ECParraN, ECParraH);
+
+            ECPublicKeyParameters ecPub = new ECPublicKeyParameters(
+                curve.ValidatePoint(ECPubQX, ECPubQY),
 				ecDomain);
 
 			ECPrivateKeyParameters ecPriv = new ECPrivateKeyParameters(ECPrivD, ecDomain);
diff --git a/crypto/test/src/security/test/TestSignerUtil.cs b/crypto/test/src/security/test/TestSignerUtil.cs
index d815d53a5..144ab67b1 100644
--- a/crypto/test/src/security/test/TestSignerUtil.cs
+++ b/crypto/test/src/security/test/TestSignerUtil.cs
@@ -56,18 +56,16 @@ namespace Org.BouncyCastle.Security.Tests
             FpCurve curve = new FpCurve(
                 new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
                 new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-                new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
+                new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16), // b
+                ECParraN, ECParraH);
 
-            ECDomainParameters ecDomain = new ECDomainParameters(curve,
-                new FpPoint(curve,
-                    curve.FromBigInteger(ECParraGX),
-                    curve.FromBigInteger(ECParraGY)),
-                ECParraN);
+            ECDomainParameters ecDomain = new ECDomainParameters(
+                curve,
+                curve.ValidatePoint(ECParraGX, ECParraGY),
+                ECParraN, ECParraH);
 
             ECPublicKeyParameters ecPub = new ECPublicKeyParameters(
-                new FpPoint(curve,
-                    curve.FromBigInteger(ECPubQX),
-                    curve.FromBigInteger(ECPubQY)),
+                curve.ValidatePoint(ECPubQX, ECPubQY),
                 ecDomain);
 
             ECPrivateKeyParameters ecPriv = new ECPrivateKeyParameters(ECPrivD, ecDomain);
diff --git a/crypto/test/src/test/CertTest.cs b/crypto/test/src/test/CertTest.cs
index 9a4965297..e3ce9df79 100644
--- a/crypto/test/src/test/CertTest.cs
+++ b/crypto/test/src/test/CertTest.cs
@@ -1391,15 +1391,9 @@ namespace Org.BouncyCastle.Tests
          */
         internal void checkCreation3()
         {
-            ECCurve curve = new FpCurve(
-                new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
-                new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-                new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
-
-            ECDomainParameters spec = new ECDomainParameters(
-                curve,
-                curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307")); // n
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("prime239v1");
+            ECCurve curve = x9.Curve;
+            ECDomainParameters spec = new ECDomainParameters(curve, x9.G, x9.N, x9.H);
 
             ECPrivateKeyParameters privKey = new ECPrivateKeyParameters(
                 "ECDSA",
@@ -1533,16 +1527,9 @@ namespace Org.BouncyCastle.Tests
             string				algorithm,
             DerObjectIdentifier	algOid)
         {
-            FpCurve curve = new FpCurve(
-                new BigInteger("6864797660130609714981900799081393217269435300143305409394463459185543183397656052122559640661454554977296311391480858037121987999716643812574028291115057151"), // q (or p)
-                new BigInteger("01FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFC", 16),   // a
-                new BigInteger("0051953EB9618E1C9A1F929A21A0B68540EEA2DA725B99B315F3B8B489918EF109E156193951EC7E937B1652C0BD3BB1BF073573DF883D2C34F1EF451FD46B503F00", 16));  // b
-
-            ECDomainParameters spec = new ECDomainParameters(
-                curve,
-//				curve.DecodePoint(Hex.Decode("02C6858E06B70404E9CD9E3ECB662395B4429C648139053FB521F828AF606B4D3DBAA14B5E77EFE75928FE1DC127A2FFA8DE3348B3C1856A429BF97E7E31C2E5BD66")), // G
-                curve.DecodePoint(Hex.Decode("0200C6858E06B70404E9CD9E3ECB662395B4429C648139053FB521F828AF606B4D3DBAA14B5E77EFE75928FE1DC127A2FFA8DE3348B3C1856A429BF97E7E31C2E5BD66")), // G
-                new BigInteger("01FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFA51868783BF2F966B7FCC0148F709A5D03BB5C9B8899C47AEBB6FB71E91386409", 16)); // n
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("secp521r1");
+            ECCurve curve = x9.Curve;
+            ECDomainParameters spec = new ECDomainParameters(curve, x9.G, x9.N, x9.H);
 
             ECPrivateKeyParameters privKey = new ECPrivateKeyParameters(
                 "ECDSA",
diff --git a/crypto/test/src/test/DHTest.cs b/crypto/test/src/test/DHTest.cs
index da31673de..f4eee348b 100644
--- a/crypto/test/src/test/DHTest.cs
+++ b/crypto/test/src/test/DHTest.cs
@@ -2,6 +2,7 @@ using System;
 
 using NUnit.Framework;
 
+using Org.BouncyCastle.Asn1.X9;
 using Org.BouncyCastle.Crypto;
 using Org.BouncyCastle.Crypto.Parameters;
 using Org.BouncyCastle.Math;
@@ -375,37 +376,22 @@ namespace Org.BouncyCastle.Tests
         [Test]
         public void TestECDH()
         {
-            doTestECDH("ECDH");
+            DoTestECDH("ECDH");
         }
 
         [Test]
         public void TestECDHC()
         {
-            doTestECDH("ECDHC");
+            DoTestECDH("ECDHC");
         }
 
-        private void doTestECDH(
-            string algorithm)
+        private void DoTestECDH(string algorithm)
         {
             IAsymmetricCipherKeyPairGenerator g = GeneratorUtilities.GetKeyPairGenerator(algorithm);
 
-//			EllipticCurve curve = new EllipticCurve(
-//				new ECFieldFp(new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839")), // q
-//				new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-//				new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
-            ECCurve curve = new FpCurve(
-                new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
-                new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-                new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
-
-            ECDomainParameters ecSpec = new ECDomainParameters(
-                curve,
-//				ECPointUtil.DecodePoint(curve, Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307"), // n
-                BigInteger.One); //1); // h
-
-//			g.initialize(ecSpec, new SecureRandom());
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("prime239v1");
+            ECDomainParameters ecSpec = new ECDomainParameters(x9.Curve, x9.G, x9.N, x9.H);
+
             g.Init(new ECKeyGenerationParameters(ecSpec, new SecureRandom()));
 
             //
@@ -429,11 +415,6 @@ namespace Org.BouncyCastle.Tests
             //
             // agreement
             //
-//			aKeyAgreeBasic.doPhase(bKeyPair.Public, true);
-//			bKeyAgreeBasic.doPhase(aKeyPair.Public, true);
-//
-//			BigInteger k1 = new BigInteger(aKeyAgreeBasic.generateSecret());
-//			BigInteger k2 = new BigInteger(bKeyAgreeBasic.generateSecret());
             BigInteger k1 = aKeyAgreeBasic.CalculateAgreement(bKeyPair.Public);
             BigInteger k2 = bKeyAgreeBasic.CalculateAgreement(aKeyPair.Public);
 
diff --git a/crypto/test/src/test/DSATest.cs b/crypto/test/src/test/DSATest.cs
index d7382d256..fb483dca7 100644
--- a/crypto/test/src/test/DSATest.cs
+++ b/crypto/test/src/test/DSATest.cs
@@ -252,15 +252,9 @@ namespace Org.BouncyCastle.Tests
 
             SecureRandom k = FixedSecureRandom.From(kData);
 
-            ECCurve curve = new FpCurve(
-                new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
-                new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-                new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
-
-            ECDomainParameters spec = new ECDomainParameters(
-                curve,
-                curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307")); // n
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("prime239v1");
+            ECCurve curve = x9.Curve;
+            ECDomainParameters spec = new ECDomainParameters(curve, x9.G, x9.N, x9.H);
 
             ECPrivateKeyParameters priKey = new ECPrivateKeyParameters(
                 "ECDSA",
@@ -330,17 +324,9 @@ namespace Org.BouncyCastle.Tests
 
             SecureRandom k = FixedSecureRandom.From(kData);
 
-            ECCurve curve = new F2mCurve(
-                239, // m
-                36, // k
-                new BigInteger("32010857077C5431123A46B808906756F543423E8D27877578125778AC76", 16), // a
-                new BigInteger("790408F2EEDAF392B012EDEFB3392F30F4327C0CA3F31FC383C422AA8C16", 16)); // b
-
-            ECDomainParameters parameters = new ECDomainParameters(
-                curve,
-                curve.DecodePoint(Hex.Decode("0457927098FA932E7C0A96D3FD5B706EF7E5F5C156E16B7E7C86038552E91D61D8EE5077C33FECF6F1A16B268DE469C3C7744EA9A971649FC7A9616305")), // G
-                new BigInteger("220855883097298041197912187592864814557886993776713230936715041207411783"), // n
-                BigInteger.ValueOf(4)); // h
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("c2tnb239v1");
+            ECCurve curve = x9.Curve;
+            ECDomainParameters parameters = new ECDomainParameters(curve, x9.G, x9.N, x9.H);
 
             ECPrivateKeyParameters sKey = new ECPrivateKeyParameters(
                 "ECDSA",
@@ -435,17 +421,9 @@ namespace Org.BouncyCastle.Tests
 
             SecureRandom k = FixedSecureRandom.From(kData);
 
-            ECCurve curve = new F2mCurve(
-                239, // m
-                36, // k
-                new BigInteger("32010857077C5431123A46B808906756F543423E8D27877578125778AC76", 16), // a
-                new BigInteger("790408F2EEDAF392B012EDEFB3392F30F4327C0CA3F31FC383C422AA8C16", 16)); // b
-
-            ECDomainParameters parameters = new ECDomainParameters(
-                curve,
-                curve.DecodePoint(Hex.Decode("0457927098FA932E7C0A96D3FD5B706EF7E5F5C156E16B7E7C86038552E91D61D8EE5077C33FECF6F1A16B268DE469C3C7744EA9A971649FC7A9616305")), // G
-                new BigInteger("220855883097298041197912187592864814557886993776713230936715041207411783"), // n
-                BigInteger.ValueOf(4)); // h
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("c2tnb239v1");
+            ECCurve curve = x9.Curve;
+            ECDomainParameters parameters = new ECDomainParameters(curve, x9.G, x9.N, x9.H);
 
             ECPrivateKeyParameters sKey = new ECPrivateKeyParameters(
                 new BigInteger("145642755521911534651321230007534120304391871461646461466464667494947990"), // d
@@ -554,15 +532,9 @@ namespace Org.BouncyCastle.Tests
             //
             s = SignerUtilities.GetSigner("ECDSA");
 
-            ECCurve curve = new FpCurve(
-                new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
-                new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-                new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
-
-            ECDomainParameters ecSpec = new ECDomainParameters(
-                curve,
-                curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307")); // n
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("prime239v1");
+            ECCurve curve = x9.Curve;
+            ECDomainParameters ecSpec = new ECDomainParameters(curve, x9.G, x9.N, x9.H);
 
             g = GeneratorUtilities.GetKeyPairGenerator("ECDSA");
             g.Init(new ECKeyGenerationParameters(ecSpec, rand));
@@ -594,17 +566,9 @@ namespace Org.BouncyCastle.Tests
             //
             s = SignerUtilities.GetSigner("ECDSA");
 
-            curve = new F2mCurve(
-                    239, // m
-                    36, // k
-                    new BigInteger("32010857077C5431123A46B808906756F543423E8D27877578125778AC76", 16), // a
-                    new BigInteger("790408F2EEDAF392B012EDEFB3392F30F4327C0CA3F31FC383C422AA8C16", 16)); // b
-
-            ecSpec = new ECDomainParameters(
-                curve,
-                curve.DecodePoint(Hex.Decode("0457927098FA932E7C0A96D3FD5B706EF7E5F5C156E16B7E7C86038552E91D61D8EE5077C33FECF6F1A16B268DE469C3C7744EA9A971649FC7A9616305")), // G
-                new BigInteger("220855883097298041197912187592864814557886993776713230936715041207411783"), // n
-                BigInteger.ValueOf(4)); // h
+            x9 = ECNamedCurveTable.GetByName("c2tnb239v1");
+            curve = x9.Curve;
+            ecSpec = new ECDomainParameters(curve, x9.G, x9.N, x9.H);
 
             g = GeneratorUtilities.GetKeyPairGenerator("ECDSA");
             g.Init(new ECKeyGenerationParameters(ecSpec, rand));
diff --git a/crypto/test/src/test/GOST3410Test.cs b/crypto/test/src/test/GOST3410Test.cs
index 931332cfb..17a079470 100644
--- a/crypto/test/src/test/GOST3410Test.cs
+++ b/crypto/test/src/test/GOST3410Test.cs
@@ -29,19 +29,21 @@ namespace Org.BouncyCastle.Tests
 
             SecureRandom k = FixedSecureRandom.From(kData);
 
-            BigInteger mod_p = new BigInteger("57896044618658097711785492504343953926634992332820282019728792003956564821041"); //p
+            BigInteger mod_p = new BigInteger("57896044618658097711785492504343953926634992332820282019728792003956564821041");
+            BigInteger mod_q = new BigInteger("57896044618658097711785492504343953927082934583725450622380973592137631069619");
 
             ECCurve curve = new FpCurve(
-                mod_p, // p
+                mod_p,
                 new BigInteger("7"), // a
-                new BigInteger("43308876546767276905765904595650931995942111794451039583252968842033849580414")); // b
+                new BigInteger("43308876546767276905765904595650931995942111794451039583252968842033849580414"), // b
+                mod_q, BigInteger.One);
 
             ECDomainParameters spec = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("2"),
                     new BigInteger("4018974056539037503335449422937059775635739389905545080690979365213431566280")),
-                new BigInteger("57896044618658097711785492504343953927082934583725450622380973592137631069619")); // q
+                mod_q, BigInteger.One);
 
             ECPrivateKeyParameters sKey = new ECPrivateKeyParameters(
                 "ECGOST3410",
@@ -193,19 +195,21 @@ namespace Org.BouncyCastle.Tests
             s = SignerUtilities.GetSigner("ECGOST3410");
             g = GeneratorUtilities.GetKeyPairGenerator("ECGOST3410");
 
-            BigInteger mod_p = new BigInteger("57896044618658097711785492504343953926634992332820282019728792003956564821041"); //p
+            BigInteger mod_p = new BigInteger("57896044618658097711785492504343953926634992332820282019728792003956564821041");
+            BigInteger mod_q = new BigInteger("57896044618658097711785492504343953927082934583725450622380973592137631069619");
 
             ECCurve curve = new FpCurve(
-                mod_p, // p
+                mod_p,
                 new BigInteger("7"), // a
-                new BigInteger("43308876546767276905765904595650931995942111794451039583252968842033849580414")); // b
+                new BigInteger("43308876546767276905765904595650931995942111794451039583252968842033849580414"), // b
+                mod_q, BigInteger.One);
 
             ECDomainParameters ecSpec = new ECDomainParameters(
                 curve,
                 curve.CreatePoint(
                     new BigInteger("2"),
                     new BigInteger("4018974056539037503335449422937059775635739389905545080690979365213431566280")),
-                new BigInteger("57896044618658097711785492504343953927082934583725450622380973592137631069619")); // q
+                mod_q, BigInteger.One);
 
             g.Init(new ECKeyGenerationParameters(ecSpec, new SecureRandom()));
 
diff --git a/crypto/test/src/test/IESTest.cs b/crypto/test/src/test/IESTest.cs
index 812b05f97..fee2d7817 100644
--- a/crypto/test/src/test/IESTest.cs
+++ b/crypto/test/src/test/IESTest.cs
@@ -32,15 +32,8 @@ namespace Org.BouncyCastle.Tests
 		{
 			IAsymmetricCipherKeyPairGenerator g = GeneratorUtilities.GetKeyPairGenerator("ECIES");
 
-			ECCurve curve = new FpCurve(
-				new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
-				new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-				new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
-
-			ECDomainParameters ecSpec = new ECDomainParameters(
-				curve,
-				curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-				new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307")); // n
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("prime239v1");
+            ECDomainParameters ecSpec = new ECDomainParameters(x9.Curve, x9.G, x9.N, x9.H);
 
 			g.Init(
 				new ECKeyGenerationParameters(
diff --git a/crypto/test/src/test/MqvTest.cs b/crypto/test/src/test/MqvTest.cs
index ec5c610ca..401fb3922 100644
--- a/crypto/test/src/test/MqvTest.cs
+++ b/crypto/test/src/test/MqvTest.cs
@@ -2,6 +2,7 @@ using System;
 
 using NUnit.Framework;
 
+using Org.BouncyCastle.Asn1.X9;
 using Org.BouncyCastle.Crypto;
 using Org.BouncyCastle.Crypto.Parameters;
 using Org.BouncyCastle.Math;
@@ -31,24 +32,10 @@ namespace Org.BouncyCastle.Tests
 		{
 			IAsymmetricCipherKeyPairGenerator g = GeneratorUtilities.GetKeyPairGenerator("ECMQV");
 
-//			EllipticCurve curve = new EllipticCurve(
-//				new ECFieldFp(new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839")), // q
-//				new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-//				new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
-			ECCurve curve = new FpCurve(
-				new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
-				new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-				new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("prime239v1");
+            ECDomainParameters ecSpec = new ECDomainParameters(x9.Curve, x9.G, x9.N, x9.H);
 
-			ECDomainParameters ecSpec = new ECDomainParameters(
-				curve,
-//				ECPointUtil.DecodePoint(curve, Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-				curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-				new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307"), // n
-				BigInteger.One); //1); // h
-
-//			g.initialize(ecSpec, new SecureRandom());
-			g.Init(new ECKeyGenerationParameters(ecSpec, new SecureRandom()));
+            g.Init(new ECKeyGenerationParameters(ecSpec, new SecureRandom()));
 			
 			//
 			// U side
diff --git a/crypto/test/src/test/PKCS10CertRequestTest.cs b/crypto/test/src/test/PKCS10CertRequestTest.cs
index 7c96baea1..df10cad3f 100644
--- a/crypto/test/src/test/PKCS10CertRequestTest.cs
+++ b/crypto/test/src/test/PKCS10CertRequestTest.cs
@@ -126,16 +126,9 @@ namespace Org.BouncyCastle.Tests
             string				algorithm,
             DerObjectIdentifier	algOid)
         {
-            FpCurve curve = new FpCurve(
-                new BigInteger("6864797660130609714981900799081393217269435300143305409394463459185543183397656052122559640661454554977296311391480858037121987999716643812574028291115057151"), // q (or p)
-                new BigInteger("01FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFC", 16),   // a
-                new BigInteger("0051953EB9618E1C9A1F929A21A0B68540EEA2DA725B99B315F3B8B489918EF109E156193951EC7E937B1652C0BD3BB1BF073573DF883D2C34F1EF451FD46B503F00", 16));  // b
-
-            ECDomainParameters spec = new ECDomainParameters(
-                curve,
-//				curve.DecodePoint(Hex.Decode("02C6858E06B70404E9CD9E3ECB662395B4429C648139053FB521F828AF606B4D3DBAA14B5E77EFE75928FE1DC127A2FFA8DE3348B3C1856A429BF97E7E31C2E5BD66")), // G
-                curve.DecodePoint(Hex.Decode("0200C6858E06B70404E9CD9E3ECB662395B4429C648139053FB521F828AF606B4D3DBAA14B5E77EFE75928FE1DC127A2FFA8DE3348B3C1856A429BF97E7E31C2E5BD66")), // G
-                new BigInteger("01FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFA51868783BF2F966B7FCC0148F709A5D03BB5C9B8899C47AEBB6FB71E91386409", 16)); // n
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("secp521r1");
+            ECCurve curve = x9.Curve;
+            ECDomainParameters spec = new ECDomainParameters(curve, x9.G, x9.N, x9.H);
 
             ECPrivateKeyParameters privKey = new ECPrivateKeyParameters(
                 new BigInteger("5769183828869504557786041598510887460263120754767955773309066354712783118202294874205844512909370791582896372147797293913785865682804434049019366394746072023"), // d
@@ -413,15 +406,9 @@ namespace Org.BouncyCastle.Tests
             // elliptic curve openSSL
             IAsymmetricCipherKeyPairGenerator g = GeneratorUtilities.GetKeyPairGenerator("ECDSA");
 
-            ECCurve curve = new FpCurve(
-                new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
-                new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-                new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
-
-            ECDomainParameters ecSpec = new ECDomainParameters(
-                curve,
-                curve.DecodePoint(Hex.Decode("020ffa963cdca8816ccc33b8642bedf905c3d358573d3f27fbbd3b3cb9aaaf")), // G
-                new BigInteger("883423532389192164791648750360308884807550341691627752275345424702807307")); // n
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("prime239v1");
+            ECCurve curve = x9.Curve;
+            ECDomainParameters ecSpec = new ECDomainParameters(curve, x9.G, x9.N, x9.H);
 
 //			g.initialize(ecSpec, new SecureRandom());
             g.Init(new ECKeyGenerationParameters(ecSpec, new SecureRandom()));
diff --git a/crypto/test/src/x509/test/TestCertificateGen.cs b/crypto/test/src/x509/test/TestCertificateGen.cs
index 019c2a460..670bf75c2 100644
--- a/crypto/test/src/x509/test/TestCertificateGen.cs
+++ b/crypto/test/src/x509/test/TestCertificateGen.cs
@@ -5,6 +5,7 @@ using System.Text;
 using NUnit.Framework;
 
 using Org.BouncyCastle.Asn1.X509;
+using Org.BouncyCastle.Asn1.X9;
 using Org.BouncyCastle.Crypto.Digests;
 using Org.BouncyCastle.Crypto.Parameters;
 using Org.BouncyCastle.Crypto.Signers;
@@ -222,20 +223,14 @@ namespace Org.BouncyCastle.X509.Tests
             BigInteger ECPubQX = new BigInteger(Base64.Decode("HWWi17Yb+Bm3PYr/DMjLOYNFhyOwX1QY7ZvqqM+l"));
             BigInteger ECPubQY = new BigInteger(Base64.Decode("JrlJfxu3WGhqwtL/55BOs/wsUeiDFsvXcGhB8DGx"));
             BigInteger ECPrivD = new BigInteger(Base64.Decode("GYQmd/NF1B+He1iMkWt3by2Az6Eu07t0ynJ4YCAo"));
-            FpCurve curve = new FpCurve(
-               new BigInteger("883423532389192164791648750360308885314476597252960362792450860609699839"), // q
-                new BigInteger("7fffffffffffffffffffffff7fffffffffff8000000000007ffffffffffc", 16), // a
-                new BigInteger("6b016c3bdcf18941d0d654921475ca71a9db2fb27d1d37796185c2942c0a", 16)); // b
-            ECDomainParameters ecDomain =
-                new ECDomainParameters(curve, new FpPoint(curve, curve.FromBigInteger(ECParraGX), curve.FromBigInteger(ECParraGY)), ECParraN);
-            ECPublicKeyParameters ecPub = new ECPublicKeyParameters(
-				"ECDSA",
-				new FpPoint(curve,
-					curve.FromBigInteger(ECPubQX),
-					curve.FromBigInteger(ECPubQY)),
-				ecDomain);
-            ECPrivateKeyParameters ecPriv = new ECPrivateKeyParameters("ECDSA", ECPrivD, ecDomain);
 
+            X9ECParameters x9 = ECNamedCurveTable.GetByName("prime239v1");
+            ECCurve curve = x9.Curve;
+            ECDomainParameters ecDomain = new ECDomainParameters(curve, curve.ValidatePoint(ECParraGX, ECParraGY), ECParraN, ECParraH);
+
+            ECPublicKeyParameters ecPub = new ECPublicKeyParameters("ECDSA",
+                curve.ValidatePoint(ECPubQX, ECPubQY), ecDomain);
+            ECPrivateKeyParameters ecPriv = new ECPrivateKeyParameters("ECDSA", ECPrivD, ecDomain);
 
             IDictionary attrs = new Hashtable();
 			attrs[X509Name.C] = "AU";