Add custom curves for secp192k1 and secp192r1 (P-192)

11 files changed, 2259 insertions, 0 deletions

diff --git a/crypto/crypto.csproj b/crypto/crypto.csproj
index 7e18a8c90..4c657b6ac 100644
--- a/crypto/crypto.csproj
+++ b/crypto/crypto.csproj
@@ -4679,11 +4679,56 @@
                     BuildAction = "Compile"
                 />
                 <File
+                    RelPath = "src\math\ec\custom\sec\Nat192.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
                     RelPath = "src\math\ec\custom\sec\Nat256.cs"
                     SubType = "Code"
                     BuildAction = "Compile"
                 />
                 <File
+                    RelPath = "src\math\ec\custom\sec\SecP192K1Curve.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "src\math\ec\custom\sec\SecP192K1Field.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "src\math\ec\custom\sec\SecP192K1FieldElement.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "src\math\ec\custom\sec\SecP192K1Point.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "src\math\ec\custom\sec\SecP192R1Curve.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "src\math\ec\custom\sec\SecP192R1Field.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "src\math\ec\custom\sec\SecP192R1FieldElement.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
+                    RelPath = "src\math\ec\custom\sec\SecP192R1Point.cs"
+                    SubType = "Code"
+                    BuildAction = "Compile"
+                />
+                <File
                     RelPath = "src\math\ec\custom\sec\SecP256K1Curve.cs"
                     SubType = "Code"
                     BuildAction = "Compile"
diff --git a/crypto/src/crypto/ec/CustomNamedCurves.cs b/crypto/src/crypto/ec/CustomNamedCurves.cs
index 72931bc7e..dcc4ea972 100644
--- a/crypto/src/crypto/ec/CustomNamedCurves.cs
+++ b/crypto/src/crypto/ec/CustomNamedCurves.cs
@@ -30,6 +30,48 @@ namespace Org.BouncyCastle.Crypto.EC
         }
 
         /*
+         * secp192k1
+         */
+        internal class Secp192k1Holder
+            : X9ECParametersHolder
+        {
+            private Secp192k1Holder() { }
+
+            internal static readonly X9ECParametersHolder Instance = new Secp192k1Holder();
+
+            protected override X9ECParameters CreateParameters()
+            {
+                byte[] S = null;
+                ECCurve curve = ConfigureCurve(new SecP192K1Curve());
+                ECPoint G = curve.DecodePoint(Hex.Decode("04"
+                    + "DB4FF10EC057E9AE26B07D0280B7F4341DA5D1B1EAE06C7D"
+                    + "9B2F2F6D9C5628A7844163D015BE86344082AA88D95E2F9D"));
+                return new X9ECParameters(curve, G, curve.Order, curve.Cofactor, S);
+            }
+        }
+
+        /*
+         * secp192r1
+         */
+        internal class Secp192r1Holder
+            : X9ECParametersHolder
+        {
+            private Secp192r1Holder() { }
+
+            internal static readonly X9ECParametersHolder Instance = new Secp192r1Holder();
+
+            protected override X9ECParameters CreateParameters()
+            {
+                byte[] S = Hex.Decode("3045AE6FC8422F64ED579528D38120EAE12196D5");
+                ECCurve curve = ConfigureCurve(new SecP192R1Curve());
+                ECPoint G = curve.DecodePoint(Hex.Decode("04"
+                    + "188DA80EB03090F67CBF20EB43A18800F4FF0AFD82FF1012"
+                    + "07192B95FFC8DA78631011ED6B24CDD573F977A11E794811"));
+                return new X9ECParameters(curve, G, curve.Order, curve.Cofactor, S);
+            }
+        }
+
+        /*
          * secp256k1
          */
         internal class Secp256k1Holder
@@ -84,9 +126,12 @@ namespace Org.BouncyCastle.Crypto.EC
 
         static CustomNamedCurves()
         {
+            DefineCurve("secp192k1", SecObjectIdentifiers.SecP192k1, Secp192k1Holder.Instance);
+            DefineCurve("secp192r1", SecObjectIdentifiers.SecP192r1, Secp192r1Holder.Instance);
             DefineCurve("secp256k1", SecObjectIdentifiers.SecP256k1, Secp256k1Holder.Instance);
             DefineCurve("secp256r1", SecObjectIdentifiers.SecP256r1, Secp256r1Holder.Instance);
 
+            objIds.Add(Platform.ToLowerInvariant("P-192"), SecObjectIdentifiers.SecP192r1);
             objIds.Add(Platform.ToLowerInvariant("P-256"), SecObjectIdentifiers.SecP256r1);
         }
 
diff --git a/crypto/src/math/ec/custom/sec/Nat192.cs b/crypto/src/math/ec/custom/sec/Nat192.cs
new file mode 100644
index 000000000..55e684cc2
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/Nat192.cs
@@ -0,0 +1,685 @@
+using System;
+using System.Diagnostics;
+
+using Org.BouncyCastle.Crypto.Utilities;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal abstract class Nat192
+    {
+        private const ulong M = 0xFFFFFFFFUL;
+
+        public static uint Add(uint[] x, uint[] y, uint[] z)
+        {
+            ulong c = 0;
+            c += (ulong)x[0] + y[0];
+            z[0] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[1] + y[1];
+            z[1] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[2] + y[2];
+            z[2] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[3] + y[3];
+            z[3] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[4] + y[4];
+            z[4] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[5] + y[5];
+            z[5] = (uint)c;
+            c >>= 32;
+            return (uint)c;
+        }
+
+        public static uint AddBothTo(uint[] x, uint[] y, uint[] z)
+        {
+            ulong c = 0;
+            c += (ulong)x[0] + y[0] + z[0];
+            z[0] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[1] + y[1] + z[1];
+            z[1] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[2] + y[2] + z[2];
+            z[2] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[3] + y[3] + z[3];
+            z[3] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[4] + y[4] + z[4];
+            z[4] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[5] + y[5] + z[5];
+            z[5] = (uint)c;
+            c >>= 32;
+            return (uint)c;
+        }
+
+        // TODO Re-write to allow full range for x?
+        public static uint AddDWord(ulong x, uint[] z, int zOff)
+        {
+            Debug.Assert(zOff < 4);
+            ulong c = x;
+            c += (ulong)z[zOff + 0];
+            z[zOff + 0] = (uint)c;
+            c >>= 32;
+            c += (ulong)z[zOff + 1];
+            z[zOff + 1] = (uint)c;
+            c >>= 32;
+            return c == 0 ? 0 : Inc(z, zOff + 2);
+        }
+
+        public static uint AddExt(uint[] xx, uint[] yy, uint[] zz)
+        {
+            ulong c = 0;
+            for (int i = 0; i < 12; ++i)
+            {
+                c += (ulong)xx[i] + yy[i];
+                zz[i] = (uint)c;
+                c >>= 32;
+            }
+            return (uint)c;
+        }
+
+        public static uint AddToExt(uint[] x, int xOff, uint[] zz, int zzOff)
+        {
+            Debug.Assert(zzOff <= 6);
+            ulong c = 0;
+            c += (ulong)x[xOff + 0] + zz[zzOff + 0];
+            zz[zzOff + 0] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[xOff + 1] + zz[zzOff + 1];
+            zz[zzOff + 1] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[xOff + 2] + zz[zzOff + 2];
+            zz[zzOff + 2] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[xOff + 3] + zz[zzOff + 3];
+            zz[zzOff + 3] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[xOff + 4] + zz[zzOff + 4];
+            zz[zzOff + 4] = (uint)c;
+            c >>= 32;
+            c += (ulong)x[xOff + 5] + zz[zzOff + 5];
+            zz[zzOff + 5] = (uint)c;
+            c >>= 32;
+            return (uint)c;
+        }
+
+        public static uint AddWordExt(uint x, uint[] zz, int zzOff)
+        {
+            Debug.Assert(zzOff < 11);
+            ulong c = (ulong)x + zz[zzOff + 0];
+            zz[zzOff + 0] = (uint)c;
+            c >>= 32;
+            return c == 0 ? 0 : IncExt(zz, zzOff + 1);
+        }
+
+        public static uint[] Create()
+        {
+            return new uint[6];
+        }
+
+        public static uint[] CreateExt()
+        {
+            return new uint[12];
+        }
+
+        public static int Dec(uint[] z, int zOff)
+        {
+            Debug.Assert(zOff < 6);
+            int i = zOff;
+            do
+            {
+                if (--z[i] != uint.MaxValue)
+                {
+                    return 0;
+                }
+            }
+            while (++i < 6);
+            return -1;
+        }
+
+        public static uint[] FromBigInteger(BigInteger x)
+        {
+            if (x.SignValue < 0 || x.BitLength > 192)
+                throw new ArgumentException();
+
+            uint[] z = Create();
+            int i = 0;
+            while (x.SignValue != 0)
+            {
+                z[i++] = (uint)x.IntValue;
+                x = x.ShiftRight(32);
+            }
+            return z;
+        }
+
+        public static uint GetBit(uint[] x, int bit)
+        {
+            if (bit == 0)
+            {
+                return x[0] & 1;
+            }
+            int w = bit >> 5;
+            if (w < 0 || w >= 6)
+            {
+                return 0;
+            }
+            int b = bit & 31;
+            return (x[w] >> b) & 1;
+        }
+
+        public static bool Gte(uint[] x, uint[] y)
+        {
+            for (int i = 5; i >= 0; --i)
+            {
+                uint x_i = x[i], y_i = y[i];
+                if (x_i < y_i)
+                    return false;
+                if (x_i > y_i)
+                    return true;
+            }
+            return false;
+        }
+
+        public static bool GteExt(uint[] xx, uint[] yy)
+        {
+            for (int i = 11; i >= 0; --i)
+            {
+                uint xx_i = xx[i], yy_i = yy[i];
+                if (xx_i < yy_i)
+                    return false;
+                if (xx_i > yy_i)
+                    return true;
+            }
+            return false;
+        }
+
+        public static uint Inc(uint[] z, int zOff)
+        {
+            Debug.Assert(zOff < 6);
+            for (int i = zOff; i < 6; ++i)
+            {
+                if (++z[i] != 0)
+                {
+                    return 0;
+                }
+            }
+            return 1;
+        }
+
+        public static uint IncExt(uint[] zz, int zzOff)
+        {
+            Debug.Assert(zzOff < 12);
+            for (int i = zzOff; i < 12; ++i)
+            {
+                if (++zz[i] != 0)
+                {
+                    return 0;
+                }
+            }
+            return 1;
+        }
+
+        public static bool IsOne(uint[] x)
+        {
+            if (x[0] != 1)
+            {
+                return false;
+            }
+            for (int i = 1; i < 6; ++i)
+            {
+                if (x[i] != 0)
+                {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        public static bool IsZero(uint[] x)
+        {
+            for (int i = 0; i < 6; ++i)
+            {
+                if (x[i] != 0)
+                {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        public static bool IsZeroExt(uint[] xx)
+        {
+            for (int i = 0; i < 12; ++i)
+            {
+                if (xx[i] != 0)
+                {
+                    return false;
+                }
+            }
+            return true;
+        }
+
+        public static void Mul(uint[] x, uint[] y, uint[] zz)
+        {
+            ulong y_0 = y[0];
+            ulong y_1 = y[1];
+            ulong y_2 = y[2];
+            ulong y_3 = y[3];
+            ulong y_4 = y[4];
+            ulong y_5 = y[5];
+
+            {
+                ulong c = 0, x_0 = x[0];
+                c += x_0 * y_0;
+                zz[0] = (uint)c;
+                c >>= 32;
+                c += x_0 * y_1;
+                zz[1] = (uint)c;
+                c >>= 32;
+                c += x_0 * y_2;
+                zz[2] = (uint)c;
+                c >>= 32;
+                c += x_0 * y_3;
+                zz[3] = (uint)c;
+                c >>= 32;
+                c += x_0 * y_4;
+                zz[4] = (uint)c;
+                c >>= 32;
+                c += x_0 * y_5;
+                zz[5] = (uint)c;
+                c >>= 32;
+                zz[6] = (uint)c;
+            }
+
+            for (int i = 1; i < 6; ++i)
+            {
+                ulong c = 0, x_i = x[i];
+                c += x_i * y_0 + zz[i + 0];
+                zz[i + 0] = (uint)c;
+                c >>= 32;
+                c += x_i * y_1 + zz[i + 1];
+                zz[i + 1] = (uint)c;
+                c >>= 32;
+                c += x_i * y_2 + zz[i + 2];
+                zz[i + 2] = (uint)c;
+                c >>= 32;
+                c += x_i * y_3 + zz[i + 3];
+                zz[i + 3] = (uint)c;
+                c >>= 32;
+                c += x_i * y_4 + zz[i + 4];
+                zz[i + 4] = (uint)c;
+                c >>= 32;
+                c += x_i * y_5 + zz[i + 5];
+                zz[i + 5] = (uint)c;
+                c >>= 32;
+                zz[i + 6] = (uint)c;
+            }
+        }
+
+        public static uint MulWordAddExt(uint x, uint[] yy, int yyOff, uint[] zz, int zzOff)
+        {
+            Debug.Assert(yyOff <= 6);
+            Debug.Assert(zzOff <= 6);
+            ulong c = 0, xVal = x;
+            c += xVal * yy[yyOff + 0] + zz[zzOff + 0];
+            zz[zzOff + 0] = (uint)c;
+            c >>= 32;
+            c += xVal * yy[yyOff + 1] + zz[zzOff + 1];
+            zz[zzOff + 1] = (uint)c;
+            c >>= 32;
+            c += xVal * yy[yyOff + 2] + zz[zzOff + 2];
+            zz[zzOff + 2] = (uint)c;
+            c >>= 32;
+            c += xVal * yy[yyOff + 3] + zz[zzOff + 3];
+            zz[zzOff + 3] = (uint)c;
+            c >>= 32;
+            c += xVal * yy[yyOff + 4] + zz[zzOff + 4];
+            zz[zzOff + 4] = (uint)c;
+            c >>= 32;
+            c += xVal * yy[yyOff + 5] + zz[zzOff + 5];
+            zz[zzOff + 5] = (uint)c;
+            c >>= 32;
+            return (uint)c;
+        }
+
+        public static uint MulWordDwordAdd(uint x, ulong y, uint[] z, int zOff)
+        {
+            Debug.Assert(zOff < 4);
+            ulong c = 0, xVal = x;
+            c += xVal * y + z[zOff + 0];
+            z[zOff + 0] = (uint)c;
+            c >>= 32;
+            c += xVal * (y >> 32) + z[zOff + 1];
+            z[zOff + 1] = (uint)c;
+            c >>= 32;
+            c += z[zOff + 2];
+            z[zOff + 2] = (uint)c;
+            c >>= 32;
+            return c == 0 ? 0 : Inc(z, zOff + 3);
+        }
+
+        public static uint MulWordExt(uint x, uint[] y, uint[] zz, int zzOff)
+        {
+            Debug.Assert(zzOff <= 6);
+            ulong c = 0, xVal = x;
+            int i = 0;
+            do
+            {
+                c += xVal * y[i];
+                zz[zzOff + i] = (uint)c;
+                c >>= 32;
+            }
+            while (++i < 6);
+            return (uint)c;
+        }
+
+        public static uint ShiftDownBit(uint[] x, int xLen, uint c)
+        {
+            int i = xLen;
+            while (--i >= 0)
+            {
+                uint next = x[i];
+                x[i] = (next >> 1) | (c << 31);
+                c = next;
+            }
+            return c << 31;
+        }
+
+        public static uint ShiftDownBit(uint[] x, uint c, uint[] z)
+        {
+            int i = 6;
+            while (--i >= 0)
+            {
+                uint next = x[i];
+                z[i] = (next >> 1) | (c << 31);
+                c = next;
+            }
+            return c << 31;
+        }
+
+        public static uint ShiftDownBits(uint[] x, int xLen, int bits, uint c)
+        {
+            Debug.Assert(bits > 0 && bits < 32);
+            int i = xLen;
+            while (--i >= 0)
+            {
+                uint next = x[i];
+                x[i] = (next >> bits) | (c << -bits);
+                c = next;
+            }
+            return c << -bits;
+        }
+
+        public static uint ShiftDownWord(uint[] x, int xLen, uint c)
+        {
+            int i = xLen;
+            while (--i >= 0)
+            {
+                uint next = x[i];
+                x[i] = c;
+                c = next;
+            }
+            return c;
+        }
+
+        public static uint ShiftUpBit(uint[] x, int xLen, uint c)
+        {
+            for (int i = 0; i < xLen; ++i)
+            {
+                uint next = x[i];
+                x[i] = (next << 1) | (c >> 31);
+                c = next;
+            }
+            return c >> 31;
+        }
+
+        public static uint ShiftUpBit(uint[] x, uint c, uint[] z)
+        {
+            for (int i = 0; i < 6; ++i)
+            {
+                uint next = x[i];
+                z[i] = (next << 1) | (c >> 31);
+                c = next;
+            }
+            return c >> 31;
+        }
+
+        public static void Square(uint[] x, uint[] zz)
+        {
+            ulong x_0 = x[0];
+            ulong zz_1;
+
+            {
+                uint c = 0;
+                int i = 5, j = 12;
+                do
+                {
+                    ulong xVal = x[i--];
+                    ulong p = xVal * xVal;
+                    zz[--j] = (c << 31) | (uint)(p >> 33);
+                    zz[--j] = (uint)(p >> 1);
+                    c = (uint)p;
+                }
+                while (i > 0);
+
+                {
+                    ulong p = x_0 * x_0;
+                    zz_1 = (ulong)(c << 31) | (p >> 33);
+                    zz[0] = (uint)(p >> 1);
+                }
+            }
+
+            ulong x_1 = x[1];
+            ulong zz_2 = zz[2];
+
+            {
+                zz_1 += x_1 * x_0;
+                zz[1] = (uint)zz_1;
+                zz_2 += zz_1 >> 32;
+            }
+
+            ulong x_2 = x[2];
+            ulong zz_3 = zz[3];
+            ulong zz_4 = zz[4];
+            {
+                zz_2 += x_2 * x_0;
+                zz[2] = (uint)zz_2;
+                zz_3 += (zz_2 >> 32) + x_2 * x_1;
+                zz_4 += zz_3 >> 32;
+                zz_3 &= M;
+            }
+
+            ulong x_3 = x[3];
+            ulong zz_5 = zz[5];
+            ulong zz_6 = zz[6];
+            {
+                zz_3 += x_3 * x_0;
+                zz[3] = (uint)zz_3;
+                zz_4 += (zz_3 >> 32) + x_3 * x_1;
+                zz_5 += (zz_4 >> 32) + x_3 * x_2;
+                zz_4 &= M;
+                zz_6 += zz_5 >> 32;
+                zz_5 &= M;
+            }
+
+            ulong x_4 = x[4];
+            ulong zz_7 = zz[7];
+            ulong zz_8 = zz[8];
+            {
+                zz_4 += x_4 * x_0;
+                zz[4] = (uint)zz_4;
+                zz_5 += (zz_4 >> 32) + x_4 * x_1;
+                zz_6 += (zz_5 >> 32) + x_4 * x_2;
+                zz_5 &= M;
+                zz_7 += (zz_6 >> 32) + x_4 * x_3;
+                zz_6 &= M;
+                zz_8 += zz_7 >> 32;
+                zz_7 &= M;
+            }
+
+            ulong x_5 = x[5];
+            ulong zz_9 = zz[9];
+            ulong zz_10 = zz[10];
+            {
+                zz_5 += x_5 * x_0;
+                zz[5] = (uint)zz_5;
+                zz_6 += (zz_5 >> 32) + x_5 * x_1;
+                zz_7 += (zz_6 >> 32) + x_5 * x_2;
+                zz_8 += (zz_7 >> 32) + x_5 * x_3;
+                zz_9 += (zz_8 >> 32) + x_5 * x_4;
+                zz_10 += zz_9 >> 32;
+            }
+
+            zz[6] = (uint)zz_6;
+            zz[7] = (uint)zz_7;
+            zz[8] = (uint)zz_8;
+            zz[9] = (uint)zz_9;
+            zz[10] = (uint)zz_10;
+            zz[11] += (uint)(zz_10 >> 32);
+
+            ShiftUpBit(zz, 12, (uint)x_0 << 31);
+        }
+
+        public static uint SquareWordAddExt(uint[] x, int xPos, uint[] zz)
+        {
+            Debug.Assert(xPos > 0 && xPos < 6);
+            ulong c = 0, xVal = x[xPos];
+            int i = 0;
+            do
+            {
+                c += xVal * x[i] + zz[xPos + i];
+                zz[xPos + i] = (uint)c;
+                c >>= 32;
+            }
+            while (++i < xPos);
+            return (uint)c;
+        }
+
+        public static int Sub(uint[] x, uint[] y, uint[] z)
+        {
+            long c = 0;
+            c += (long)x[0] - y[0];
+            z[0] = (uint)c;
+            c >>= 32;
+            c += (long)x[1] - y[1];
+            z[1] = (uint)c;
+            c >>= 32;
+            c += (long)x[2] - y[2];
+            z[2] = (uint)c;
+            c >>= 32;
+            c += (long)x[3] - y[3];
+            z[3] = (uint)c;
+            c >>= 32;
+            c += (long)x[4] - y[4];
+            z[4] = (uint)c;
+            c >>= 32;
+            c += (long)x[5] - y[5];
+            z[5] = (uint)c;
+            c >>= 32;
+            return (int)c;
+        }
+
+        public static int SubBothFrom(uint[] x, uint[] y, uint[] z)
+        {
+            long c = 0;
+            c += (long)z[0] - x[0] - y[0];
+            z[0] = (uint)c;
+            c >>= 32;
+            c += (long)z[1] - x[1] - y[1];
+            z[1] = (uint)c;
+            c >>= 32;
+            c += (long)z[2] - x[2] - y[2];
+            z[2] = (uint)c;
+            c >>= 32;
+            c += (long)z[3] - x[3] - y[3];
+            z[3] = (uint)c;
+            c >>= 32;
+            c += (long)z[4] - x[4] - y[4];
+            z[4] = (uint)c;
+            c >>= 32;
+            c += (long)z[5] - x[5] - y[5];
+            z[5] = (uint)c;
+            c >>= 32;
+            return (int)c;
+        }
+
+        // TODO Re-write to allow full range for x?
+        public static int SubDWord(ulong x, uint[] z)
+        {
+            long c = -(long)x;
+            c += (long)z[0];
+            z[0] = (uint)c;
+            c >>= 32;
+            c += (long)z[1];
+            z[1] = (uint)c;
+            c >>= 32;
+            return c == 0 ? 0 : Dec(z, 2);
+        }
+
+        public static int SubExt(uint[] xx, uint[] yy, uint[] zz)
+        {
+            long c = 0;
+            for (int i = 0; i < 12; ++i)
+            {
+                c += (long)xx[i] - yy[i];
+                zz[i] = (uint)c;
+                c >>= 32;
+            }
+            return (int)c;
+        }
+
+        public static int SubFromExt(uint[] x, int xOff, uint[] zz, int zzOff)
+        {
+            Debug.Assert(zzOff <= 6);
+            long c = 0;
+            c += (long)zz[zzOff + 0] - x[xOff + 0];
+            zz[zzOff + 0] = (uint)c;
+            c >>= 32;
+            c += (long)zz[zzOff + 1] - x[xOff + 1];
+            zz[zzOff + 1] = (uint)c;
+            c >>= 32;
+            c += (long)zz[zzOff + 2] - x[xOff + 2];
+            zz[zzOff + 2] = (uint)c;
+            c >>= 32;
+            c += (long)zz[zzOff + 3] - x[xOff + 3];
+            zz[zzOff + 3] = (uint)c;
+            c >>= 32;
+            c += (long)zz[zzOff + 4] - x[xOff + 4];
+            zz[zzOff + 4] = (uint)c;
+            c >>= 32;
+            c += (long)zz[zzOff + 5] - x[xOff + 5];
+            zz[zzOff + 5] = (uint)c;
+            c >>= 32;
+            return (int)c;
+        }
+
+        public static BigInteger ToBigInteger(uint[] x)
+        {
+            byte[] bs = new byte[24];
+            for (int i = 0; i < 6; ++i)
+            {
+                uint x_i = x[i];
+                if (x_i != 0)
+                {
+                    Pack.UInt32_To_BE(x_i, bs, (5 - i) << 2);
+                }
+            }
+            return new BigInteger(1, bs);
+        }
+
+        public static void Zero(uint[] z)
+        {
+            z[0] = 0;
+            z[1] = 0;
+            z[2] = 0;
+            z[3] = 0;
+            z[4] = 0;
+            z[5] = 0;
+        }
+    }
+}
diff --git a/crypto/src/math/ec/custom/sec/SecP192K1Curve.cs b/crypto/src/math/ec/custom/sec/SecP192K1Curve.cs
new file mode 100644
index 000000000..ab509b9fa
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecP192K1Curve.cs
@@ -0,0 +1,93 @@
+using System;
+
+using Org.BouncyCastle.Math.Field;
+using Org.BouncyCastle.Utilities.Encoders;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecP192K1Curve
+        : ECCurve
+    {
+        public static readonly BigInteger q = new BigInteger(1,
+            Hex.Decode("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFEE37"));
+
+        private const int SECP192K1_DEFAULT_COORDS = COORD_JACOBIAN;
+
+        protected readonly SecP192K1Point m_infinity;
+
+        public SecP192K1Curve()
+            : base(FiniteFields.GetPrimeField(q))
+        {
+            this.m_infinity = new SecP192K1Point(this, null, null);
+
+            this.m_a = FromBigInteger(BigInteger.Zero);
+            this.m_b = FromBigInteger(BigInteger.ValueOf(3));
+            this.m_order = new BigInteger(1, Hex.Decode("FFFFFFFFFFFFFFFFFFFFFFFE26F2FC170F69466A74DEFD8D"));
+            this.m_cofactor = BigInteger.One;
+            this.m_coord = SECP192K1_DEFAULT_COORDS;
+        }
+
+        protected override ECCurve CloneCurve()
+        {
+            return new SecP192K1Curve();
+        }
+
+        public override bool SupportsCoordinateSystem(int coord)
+        {
+            switch (coord)
+            {
+                case COORD_JACOBIAN:
+                    return true;
+                default:
+                    return false;
+            }
+        }
+
+        public virtual BigInteger Q
+        {
+            get { return q; }
+        }
+
+        public override ECPoint Infinity
+        {
+            get { return m_infinity; }
+        }
+
+        public override int FieldSize
+        {
+            get { return q.BitLength; }
+        }
+
+        public override ECFieldElement FromBigInteger(BigInteger x)
+        {
+            return new SecP192K1FieldElement(x);
+        }
+
+        protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, bool withCompression)
+        {
+            return new SecP192K1Point(this, x, y, withCompression);
+        }
+
+        protected override ECPoint DecompressPoint(int yTilde, BigInteger X1)
+        {
+            ECFieldElement x = FromBigInteger(X1);
+            ECFieldElement alpha = x.Square().Multiply(x).Add(B);
+            ECFieldElement beta = alpha.Sqrt();
+
+            //
+            // if we can't find a sqrt we haven't got a point on the
+            // curve - run!
+            //
+            if (beta == null)
+                throw new ArithmeticException("Invalid point compression");
+
+            if (beta.TestBitZero() != (yTilde == 1))
+            {
+                // Use the other root
+                beta = beta.Negate();
+            }
+
+            return new SecP192K1Point(this, x, beta, true);
+        }
+    }
+}
diff --git a/crypto/src/math/ec/custom/sec/SecP192K1Field.cs b/crypto/src/math/ec/custom/sec/SecP192K1Field.cs
new file mode 100644
index 000000000..30c107c86
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecP192K1Field.cs
@@ -0,0 +1,156 @@
+using System;
+using System.Diagnostics;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecP192K1Field
+    {
+        // 2^192 - 2^32 - 2^12 - 2^8 - 2^7 - 2^6 - 2^3 - 1
+        internal static readonly uint[] P = new uint[]{ 0xFFFFEE37, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
+        private const uint P5 = 0xFFFFFFFF;
+        private static readonly uint[] PExt = new uint[]{ 0x013C4FD1, 0x00002392, 0x00000001, 0x00000000, 0x00000000,
+            0x00000000, 0xFFFFDC6E, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
+        private const uint PExt11 = 0xFFFFFFFF;
+        private const ulong PInv = 0x00000001000011C9L;
+        private const uint PInvLow = 0x11C9;
+
+        public static void Add(uint[] x, uint[] y, uint[] z)
+        {
+            uint c = Nat192.Add(x, y, z);
+            if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P)))
+            {
+                Nat192.AddDWord(PInv, z, 0);
+            }
+        }
+
+        public static void AddExt(uint[] xx, uint[] yy, uint[] zz)
+        {
+            uint c = Nat192.AddExt(xx, yy, zz);
+            if (c != 0 || (zz[11] == PExt11 && Nat192.GteExt(zz, PExt)))
+            {
+                Nat192.SubExt(zz, PExt, zz);
+            }
+        }
+
+        public static void AddOne(uint[] x, uint[] z)
+        {
+            Array.Copy(x, 0, z, 0, 6);
+            uint c = Nat192.Inc(z, 0);
+            if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P)))
+            {
+                Nat192.AddDWord(PInv, z, 0);
+            }
+        }
+
+        public static uint[] FromBigInteger(BigInteger x)
+        {
+            uint[] z = Nat192.FromBigInteger(x);
+            if (z[5] == P5 && Nat192.Gte(z, P))
+            {
+                Nat192.AddDWord(PInv, z, 0);
+            }
+            return z;
+        }
+
+        public static void Half(uint[] x, uint[] z)
+        {
+            if ((x[0] & 1) == 0)
+            {
+                Nat192.ShiftDownBit(x, 0, z);
+            }
+            else
+            {
+                uint c = Nat192.Add(x, P, z);
+                Nat192.ShiftDownBit(z, c, z);
+            }
+        }
+
+        public static void Multiply(uint[] x, uint[] y, uint[] z)
+        {
+            uint[] tt = Nat192.CreateExt();
+            Nat192.Mul(x, y, tt);
+            Reduce(tt, z);
+        }
+
+        public static void Negate(uint[] x, uint[] z)
+        {
+            if (Nat192.IsZero(x))
+            {
+                Nat192.Zero(z);
+            }
+            else
+            {
+                Nat192.Sub(P, x, z);
+            }
+        }
+
+        public static void Reduce(uint[] tt, uint[] z)
+        {
+            long extra = -(long)tt[6];
+            extra += (long)Nat192.MulWordAddExt(PInvLow, tt, 6, tt, 0);
+            extra += (long)Nat192.AddToExt(tt, 6, tt, 1) << 32;
+            extra += (long)tt[6];
+
+            ulong c = Nat192.MulWordDwordAdd(PInvLow, (ulong)extra, tt, 0);
+            c += Nat192.AddDWord((ulong)extra, tt, 1);
+
+            Debug.Assert(c == 0 || c == 1);
+
+            if (c != 0 || (tt[5] == P5 && Nat192.Gte(tt, P)))
+            {
+                Nat192.AddDWord(PInv, tt, 0);
+            }
+
+            Array.Copy(tt, 0, z, 0, 6);
+        }
+
+        public static void Square(uint[] x, uint[] z)
+        {
+            uint[] tt = Nat192.CreateExt();
+            Nat192.Square(x, tt);
+            Reduce(tt, z);
+        }
+
+        public static void SquareN(uint[] x, int n, uint[] z)
+        {
+            Debug.Assert(n > 0);
+
+            uint[] tt = Nat192.CreateExt();
+            Nat192.Square(x, tt);
+            Reduce(tt, z);
+
+            while (--n > 0)
+            {
+                Nat192.Square(z, tt);
+                Reduce(tt, z);
+            }
+        }
+
+        public static void Subtract(uint[] x, uint[] y, uint[] z)
+        {
+            int c = Nat192.Sub(x, y, z);
+            if (c != 0)
+            {
+                Nat192.SubDWord(PInv, z);
+            }
+        }
+
+        public static void SubtractExt(uint[] xx, uint[] yy, uint[] zz)
+        {
+            int c = Nat192.SubExt(xx, yy, zz);
+            if (c != 0)
+            {
+                Nat192.AddExt(zz, PExt, zz);
+            }
+        }
+
+        public static void Twice(uint[] x, uint[] z)
+        {
+            uint c = Nat192.ShiftUpBit(x, 0, z);
+            if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P)))
+            {
+                Nat192.AddDWord(PInv, z, 0);
+            }
+        }
+    }
+}
diff --git a/crypto/src/math/ec/custom/sec/SecP192K1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP192K1FieldElement.cs
new file mode 100644
index 000000000..2d1f79367
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecP192K1FieldElement.cs
@@ -0,0 +1,214 @@
+using System;
+using System.Diagnostics;
+
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecP192K1FieldElement
+        : ECFieldElement
+    {
+        public static readonly BigInteger Q = SecP192K1Curve.q;
+
+        protected internal readonly uint[] x;
+
+        public SecP192K1FieldElement(BigInteger x)
+        {
+            if (x == null || x.SignValue < 0 || x.CompareTo(Q) >= 0)
+                throw new ArgumentException("value invalid for SecP192K1FieldElement", "x");
+
+            this.x = SecP192K1Field.FromBigInteger(x);
+        }
+
+        public SecP192K1FieldElement()
+        {
+            this.x = Nat192.Create();
+        }
+
+        protected internal SecP192K1FieldElement(uint[] x)
+        {
+            this.x = x;
+        }
+
+        public override bool IsZero
+        {
+            get { return Nat192.IsZero(x); }
+        }
+
+        public override bool IsOne
+        {
+            get { return Nat192.IsOne(x); }
+        }
+
+        public override bool TestBitZero()
+        {
+            return Nat192.GetBit(x, 0) == 1;
+        }
+
+        public override BigInteger ToBigInteger()
+        {
+            return Nat192.ToBigInteger(x);
+        }
+
+        public override string FieldName
+        {
+            get { return "SecP192K1Field"; }
+        }
+
+        public override int FieldSize
+        {
+            get { return Q.BitLength; }
+        }
+
+        public override ECFieldElement Add(ECFieldElement b)
+        {
+            uint[] z = Nat192.Create();
+            SecP192K1Field.Add(x, ((SecP192K1FieldElement)b).x, z);
+            return new SecP192K1FieldElement(z);
+        }
+
+        public override ECFieldElement AddOne()
+        {
+            uint[] z = Nat192.Create();
+            SecP192K1Field.AddOne(x, z);
+            return new SecP192K1FieldElement(z);
+        }
+
+        public override ECFieldElement Subtract(ECFieldElement b)
+        {
+            uint[] z = Nat192.Create();
+            SecP192K1Field.Subtract(x, ((SecP192K1FieldElement)b).x, z);
+            return new SecP192K1FieldElement(z);
+        }
+
+        public override ECFieldElement Multiply(ECFieldElement b)
+        {
+            uint[] z = Nat192.Create();
+            SecP192K1Field.Multiply(x, ((SecP192K1FieldElement)b).x, z);
+            return new SecP192K1FieldElement(z);
+        }
+
+        public override ECFieldElement Divide(ECFieldElement b)
+        {
+            //return Multiply(b.Invert());
+            uint[] z = Nat192.Create();
+            Mod.Invert(SecP192K1Field.P, ((SecP192K1FieldElement)b).x, z);
+            SecP192K1Field.Multiply(z, x, z);
+            return new SecP192K1FieldElement(z);
+        }
+
+        public override ECFieldElement Negate()
+        {
+            uint[] z = Nat192.Create();
+            SecP192K1Field.Negate(x, z);
+            return new SecP192K1FieldElement(z);
+        }
+
+        public override ECFieldElement Square()
+        {
+            uint[] z = Nat192.Create();
+            SecP192K1Field.Square(x, z);
+            return new SecP192K1FieldElement(z);
+        }
+
+        public override ECFieldElement Invert()
+        {
+            //return new SecP192K1FieldElement(ToBigInteger().ModInverse(Q));
+            uint[] z = Nat192.Create();
+            Mod.Invert(SecP192K1Field.P, x, z);
+            return new SecP192K1FieldElement(z);
+        }
+
+        /**
+         * return a sqrt root - the routine verifies that the calculation returns the right value - if
+         * none exists it returns null.
+         */
+        public override ECFieldElement Sqrt()
+        {
+            /*
+             * Raise this element to the exponent 2^190 - 2^30 - 2^10 - 2^6 - 2^5 - 2^4 - 2^1
+             * 
+             * Breaking up the exponent's binary representation into "repunits", we get:
+             * { 159 1s } { 1 0s } { 19 1s } { 1 0s } { 3 1s } { 3 0s} { 3 1s } { 1 0s }
+             * 
+             * Therefore we need an addition chain containing 3, 19, 159 (the lengths of the repunits)
+             * We use: 1, 2, [3], 6, 8, 16, [19], 35, 70, 140, [159]
+             */
+
+            uint[] x1 = this.x;
+            if (Nat192.IsZero(x1) || Nat192.IsOne(x1))
+            {
+                return this;
+            }
+
+            uint[] x2 = Nat192.Create();
+            SecP192K1Field.Square(x1, x2);
+            SecP192K1Field.Multiply(x2, x1, x2);
+            uint[] x3 = Nat192.Create();
+            SecP192K1Field.Square(x2, x3);
+            SecP192K1Field.Multiply(x3, x1, x3);
+            uint[] x6 = Nat192.Create();
+            SecP192K1Field.SquareN(x3, 3, x6);
+            SecP192K1Field.Multiply(x6, x3, x6);
+            uint[] x8 = x6;
+            SecP192K1Field.SquareN(x6, 2, x8);
+            SecP192K1Field.Multiply(x8, x2, x8);
+            uint[] x16 = x2;
+            SecP192K1Field.SquareN(x8, 8, x16);
+            SecP192K1Field.Multiply(x16, x8, x16);
+            uint[] x19 = x8;
+            SecP192K1Field.SquareN(x16, 3, x19);
+            SecP192K1Field.Multiply(x19, x3, x19);
+            uint[] x35 = Nat192.Create();
+            SecP192K1Field.SquareN(x19, 16, x35);
+            SecP192K1Field.Multiply(x35, x16, x35);
+            uint[] x70 = x16;
+            SecP192K1Field.SquareN(x35, 35, x70);
+            SecP192K1Field.Multiply(x70, x35, x70);
+            uint[] x140 = x35;
+            SecP192K1Field.SquareN(x70, 70, x140);
+            SecP192K1Field.Multiply(x140, x70, x140);
+            uint[] x159 = x70;
+            SecP192K1Field.SquareN(x140, 19, x159);
+            SecP192K1Field.Multiply(x159, x19, x159);
+
+            uint[] t1 = x159;
+            SecP192K1Field.SquareN(t1, 20, t1);
+            SecP192K1Field.Multiply(t1, x19, t1);
+            SecP192K1Field.SquareN(t1, 4, t1);
+            SecP192K1Field.Multiply(t1, x3, t1);
+            SecP192K1Field.SquareN(t1, 6, t1);
+            SecP192K1Field.Multiply(t1, x3, t1);
+            SecP192K1Field.Square(t1, t1);
+
+            uint[] t2 = x3;
+            SecP192K1Field.Square(t1, t2);
+
+            return Arrays.AreEqual(x1, t2) ? new SecP192K1FieldElement(t1) : null;
+        }
+
+        public override bool Equals(object obj)
+        {
+            return Equals(obj as SecP192K1FieldElement);
+        }
+
+        public override bool Equals(ECFieldElement other)
+        {
+            return Equals(other as SecP192K1FieldElement);
+        }
+
+        public virtual bool Equals(SecP192K1FieldElement other)
+        {
+            if (this == other)
+                return true;
+            if (null == other)
+                return false;
+            return Arrays.AreEqual(x, other.x);
+        }
+
+        public override int GetHashCode()
+        {
+            return Q.GetHashCode() ^ Arrays.GetHashCode(x);
+        }
+    }
+}
diff --git a/crypto/src/math/ec/custom/sec/SecP192K1Point.cs b/crypto/src/math/ec/custom/sec/SecP192K1Point.cs
new file mode 100644
index 000000000..364c62480
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecP192K1Point.cs
@@ -0,0 +1,276 @@
+using System;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecP192K1Point
+        : ECPointBase
+    {
+        /**
+         * Create a point which encodes with point compression.
+         * 
+         * @param curve
+         *            the curve to use
+         * @param x
+         *            affine x co-ordinate
+         * @param y
+         *            affine y co-ordinate
+         * 
+         * @deprecated Use ECCurve.createPoint to construct points
+         */
+        public SecP192K1Point(ECCurve curve, ECFieldElement x, ECFieldElement y)
+            : this(curve, x, y, false)
+        {
+        }
+
+        /**
+         * Create a point that encodes with or without point compresion.
+         * 
+         * @param curve
+         *            the curve to use
+         * @param x
+         *            affine x co-ordinate
+         * @param y
+         *            affine y co-ordinate
+         * @param withCompression
+         *            if true encode with point compression
+         * 
+         * @deprecated per-point compression property will be removed, refer
+         *             {@link #getEncoded(bool)}
+         */
+        public SecP192K1Point(ECCurve curve, ECFieldElement x, ECFieldElement y, bool withCompression)
+            : base(curve, x, y, withCompression)
+        {
+            if ((x == null) != (y == null))
+                throw new ArgumentException("Exactly one of the field elements is null");
+        }
+
+        internal SecP192K1Point(ECCurve curve, ECFieldElement x, ECFieldElement y, ECFieldElement[] zs,
+            bool withCompression)
+            : base(curve, x, y, zs, withCompression)
+        {
+        }
+
+        protected override ECPoint Detach()
+        {
+            return new SecP192K1Point(null, AffineXCoord, AffineYCoord);
+        }
+
+        protected internal override bool CompressionYTilde
+        {
+            get { return this.AffineYCoord.TestBitZero(); }
+        }
+
+        public override ECPoint Add(ECPoint b)
+        {
+            if (this.IsInfinity)
+                return b;
+            if (b.IsInfinity)
+                return this;
+            if (this == b)
+                return Twice();
+
+            ECCurve curve = this.Curve;
+
+            SecP192K1FieldElement X1 = (SecP192K1FieldElement)this.RawXCoord, Y1 = (SecP192K1FieldElement)this.RawYCoord;
+            SecP192K1FieldElement X2 = (SecP192K1FieldElement)b.RawXCoord, Y2 = (SecP192K1FieldElement)b.RawYCoord;
+
+            SecP192K1FieldElement Z1 = (SecP192K1FieldElement)this.RawZCoords[0];
+            SecP192K1FieldElement Z2 = (SecP192K1FieldElement)b.RawZCoords[0];
+
+            uint[] tt1 = Nat192.CreateExt();
+            uint[] tt2 = Nat192.CreateExt();
+            uint[] t3 = Nat192.Create();
+            uint[] t4 = Nat192.Create();
+
+            bool Z1IsOne = Z1.IsOne;
+            uint[] U2, S2;
+            if (Z1IsOne)
+            {
+                U2 = X2.x;
+                S2 = Y2.x;
+            }
+            else
+            {
+                S2 = t3;
+                SecP192K1Field.Square(Z1.x, S2);
+
+                U2 = tt2;
+                SecP192K1Field.Multiply(S2, X2.x, U2);
+
+                SecP192K1Field.Multiply(S2, Z1.x, S2);
+                SecP192K1Field.Multiply(S2, Y2.x, S2);
+            }
+
+            bool Z2IsOne = Z2.IsOne;
+            uint[] U1, S1;
+            if (Z2IsOne)
+            {
+                U1 = X1.x;
+                S1 = Y1.x;
+            }
+            else
+            {
+                S1 = t4;
+                SecP192K1Field.Square(Z2.x, S1);
+
+                U1 = tt1;
+                SecP192K1Field.Multiply(S1, X1.x, U1);
+
+                SecP192K1Field.Multiply(S1, Z2.x, S1);
+                SecP192K1Field.Multiply(S1, Y1.x, S1);
+            }
+
+            uint[] H = Nat192.Create();
+            SecP192K1Field.Subtract(U1, U2, H);
+
+            uint[] R = tt2;
+            SecP192K1Field.Subtract(S1, S2, R);
+
+            // Check if b == this or b == -this
+            if (Nat192.IsZero(H))
+            {
+                if (Nat192.IsZero(R))
+                {
+                    // this == b, i.e. this must be doubled
+                    return this.Twice();
+                }
+
+                // this == -b, i.e. the result is the point at infinity
+                return curve.Infinity;
+            }
+
+            uint[] HSquared = t3;
+            SecP192K1Field.Square(H, HSquared);
+
+            uint[] G = Nat192.Create();
+            SecP192K1Field.Multiply(HSquared, H, G);
+
+            uint[] V = t3;
+            SecP192K1Field.Multiply(HSquared, U1, V);
+
+            Nat192.Mul(S1, G, tt1);
+
+            SecP192K1FieldElement X3 = new SecP192K1FieldElement(t4);
+            SecP192K1Field.Square(R, X3.x);
+            SecP192K1Field.Add(X3.x, G, X3.x);
+            SecP192K1Field.Subtract(X3.x, V, X3.x);
+            SecP192K1Field.Subtract(X3.x, V, X3.x);
+
+            SecP192K1FieldElement Y3 = new SecP192K1FieldElement(G);
+            SecP192K1Field.Subtract(V, X3.x, Y3.x);
+            Nat192.Mul(Y3.x, R, tt2);
+            SecP192K1Field.SubtractExt(tt2, tt1, tt2);
+            SecP192K1Field.Reduce(tt2, Y3.x);
+
+            SecP192K1FieldElement Z3 = new SecP192K1FieldElement(H);
+            if (!Z1IsOne)
+            {
+                SecP192K1Field.Multiply(Z3.x, Z1.x, Z3.x);
+            }
+            if (!Z2IsOne)
+            {
+                SecP192K1Field.Multiply(Z3.x, Z2.x, Z3.x);
+            }
+
+            ECFieldElement[] zs = new ECFieldElement[] { Z3 };
+
+            return new SecP192K1Point(curve, X3, Y3, zs, IsCompressed);
+        }
+
+        public override ECPoint Twice()
+        {
+            if (this.IsInfinity)
+                return this;
+
+            ECCurve curve = this.Curve;
+
+            SecP192K1FieldElement Y1 = (SecP192K1FieldElement)this.RawYCoord;
+            if (Y1.IsZero)
+                return curve.Infinity;
+
+            SecP192K1FieldElement X1 = (SecP192K1FieldElement)this.RawXCoord, Z1 = (SecP192K1FieldElement)this.RawZCoords[0];
+
+            uint[] Y1Squared = Nat192.Create();
+            SecP192K1Field.Square(Y1.x, Y1Squared);
+
+            uint[] T = Nat192.Create();
+            SecP192K1Field.Square(Y1Squared, T);
+
+            uint[] t1 = Nat192.Create();
+            SecP192K1Field.Square(X1.x, t1);
+
+            uint[] M = Nat192.Create();
+            SecP192K1Field.Twice(t1, M);
+            SecP192K1Field.Add(M, t1, M);
+
+            uint[] S = Y1Squared;
+            SecP192K1Field.Multiply(Y1Squared, X1.x, S);
+            SecP192K1Field.Twice(S, S);
+            SecP192K1Field.Twice(S, S);
+
+            SecP192K1Field.Twice(T, t1);
+            SecP192K1Field.Twice(t1, t1);
+            SecP192K1Field.Twice(t1, t1);
+
+            SecP192K1FieldElement X3 = new SecP192K1FieldElement(T);
+            SecP192K1Field.Square(M, X3.x);
+            SecP192K1Field.Subtract(X3.x, S, X3.x);
+            SecP192K1Field.Subtract(X3.x, S, X3.x);
+
+            SecP192K1FieldElement Y3 = new SecP192K1FieldElement(S);
+            SecP192K1Field.Subtract(S, X3.x, Y3.x);
+            SecP192K1Field.Multiply(Y3.x, M, Y3.x);
+            SecP192K1Field.Subtract(Y3.x, t1, Y3.x);
+
+            SecP192K1FieldElement Z3 = new SecP192K1FieldElement(M);
+            SecP192K1Field.Twice(Y1.x, Z3.x);
+            if (!Z1.IsOne)
+            {
+                SecP192K1Field.Multiply(Z3.x, Z1.x, Z3.x);
+            }
+
+            return new SecP192K1Point(curve, X3, Y3, new ECFieldElement[] { Z3 }, IsCompressed);
+        }
+
+        public override ECPoint TwicePlus(ECPoint b)
+        {
+            if (this == b)
+                return ThreeTimes();
+            if (this.IsInfinity)
+                return b;
+            if (b.IsInfinity)
+                return Twice();
+
+            ECFieldElement Y1 = this.RawYCoord;
+            if (Y1.IsZero)
+                return b;
+
+            return Twice().Add(b);
+        }
+
+        public override ECPoint ThreeTimes()
+        {
+            if (this.IsInfinity || this.RawYCoord.IsZero)
+                return this;
+
+            // NOTE: Be careful about recursions between TwicePlus and ThreeTimes
+            return Twice().Add(this);
+        }
+
+        public override ECPoint Subtract(ECPoint b)
+        {
+            if (b.IsInfinity)
+                return this;
+
+            return Add(b.Negate());
+        }
+
+        public override ECPoint Negate()
+        {
+            if (IsInfinity)
+                return this;
+
+            return new SecP192K1Point(Curve, RawXCoord, RawYCoord.Negate(), RawZCoords, IsCompressed);
+        }
+    }
+}
diff --git a/crypto/src/math/ec/custom/sec/SecP192R1Curve.cs b/crypto/src/math/ec/custom/sec/SecP192R1Curve.cs
new file mode 100644
index 000000000..62cb6f510
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecP192R1Curve.cs
@@ -0,0 +1,96 @@
+using System;
+
+using Org.BouncyCastle.Math.Field;
+using Org.BouncyCastle.Utilities.Encoders;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecP192R1Curve
+        : ECCurve
+    {
+        public static readonly BigInteger q = new BigInteger(1,
+            Hex.Decode("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFFFFFFFFFF"));
+
+        private const int SecP192R1_DEFAULT_COORDS = COORD_JACOBIAN;
+
+        protected readonly SecP192R1Point m_infinity;
+
+        public SecP192R1Curve()
+            : base(FiniteFields.GetPrimeField(q))
+        {
+            this.m_infinity = new SecP192R1Point(this, null, null);
+
+            this.m_a = FromBigInteger(new BigInteger(1,
+                Hex.Decode("FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEFFFFFFFFFFFFFFFC")));
+            this.m_b = FromBigInteger(new BigInteger(1,
+                Hex.Decode("64210519E59C80E70FA7E9AB72243049FEB8DEECC146B9B1")));
+            this.m_order = new BigInteger(1, Hex.Decode("FFFFFFFFFFFFFFFFFFFFFFFF99DEF836146BC9B1B4D22831"));
+            this.m_cofactor = BigInteger.One;
+
+            this.m_coord = SecP192R1_DEFAULT_COORDS;
+        }
+
+        protected override ECCurve CloneCurve()
+        {
+            return new SecP192R1Curve();
+        }
+
+        public override bool SupportsCoordinateSystem(int coord)
+        {
+            switch (coord)
+            {
+            case COORD_JACOBIAN:
+                return true;
+            default:
+                return false;
+            }
+        }
+
+        public virtual BigInteger Q
+        {
+            get { return q; }
+        }
+
+        public override ECPoint Infinity
+        {
+            get { return m_infinity; }
+        }
+
+        public override int FieldSize
+        {
+            get { return q.BitLength; }
+        }
+
+        public override ECFieldElement FromBigInteger(BigInteger x)
+        {
+            return new SecP192R1FieldElement(x);
+        }
+
+        protected internal override ECPoint CreateRawPoint(ECFieldElement x, ECFieldElement y, bool withCompression)
+        {
+            return new SecP192R1Point(this, x, y, withCompression);
+        }
+
+        protected override ECPoint DecompressPoint(int yTilde, BigInteger X1)
+        {
+            ECFieldElement x = FromBigInteger(X1);
+            ECFieldElement alpha = x.Square().Add(A).Multiply(x).Add(B);
+            ECFieldElement beta = alpha.Sqrt();
+
+            //
+            // if we can't find a sqrt we haven't got a point on the
+            // curve - run!
+            //
+            if (beta == null)
+                throw new ArithmeticException("Invalid point compression");
+
+            if (beta.TestBitZero() != (yTilde == 1))
+            {
+                // Use the other root
+                beta = beta.Negate();
+            }
+
+            return new SecP192R1Point(this, x, beta, true);
+        }
+    }
+}
diff --git a/crypto/src/math/ec/custom/sec/SecP192R1Field.cs b/crypto/src/math/ec/custom/sec/SecP192R1Field.cs
new file mode 100644
index 000000000..5f3ecacc4
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecP192R1Field.cs
@@ -0,0 +1,172 @@
+using System;
+using System.Diagnostics;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecP192R1Field
+    {
+        // 2^192 - 2^64 - 1
+        internal static readonly uint[] P = new uint[]{ 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
+        private const uint P5 = 0xFFFFFFFF;
+        private static readonly uint[] PExt = new uint[]{ 0x00000001, 0x00000000, 0x00000002, 0x00000000, 0x00000001,
+            0x00000000, 0xFFFFFFFE, 0xFFFFFFFF, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF };
+        private const uint PExt11 = 0xFFFFFFFF;
+
+        public static void Add(uint[] x, uint[] y, uint[] z)
+        {
+            uint c = Nat192.Add(x, y, z);
+            if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P)))
+            {
+                Nat192.Sub(z, P, z);
+            }
+        }
+
+        public static void AddExt(uint[] xx, uint[] yy, uint[] zz)
+        {
+            uint c = Nat192.AddExt(xx, yy, zz);
+            if (c != 0 || (zz[11] == PExt11 && Nat192.GteExt(zz, PExt)))
+            {
+                Nat192.SubExt(zz, PExt, zz);
+            }
+        }
+
+        public static void AddOne(uint[] x, uint[] z)
+        {
+            Array.Copy(x, 0, z, 0, 6);
+            uint c = Nat192.Inc(z, 0);
+            if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P)))
+            {
+                Nat192.Sub(z, P, z);
+            }
+        }
+
+        public static uint[] FromBigInteger(BigInteger x)
+        {
+            uint[] z = Nat192.FromBigInteger(x);
+            if (z[5] == P5 && Nat192.Gte(z, P))
+            {
+                Nat192.Sub(z, P, z);
+            }
+            return z;
+        }
+
+        public static void Half(uint[] x, uint[] z)
+        {
+            if ((x[0] & 1) == 0)
+            {
+                Nat192.ShiftDownBit(x, 0, z);
+            }
+            else
+            {
+                uint c = Nat192.Add(x, P, z);
+                Nat192.ShiftDownBit(z, c, z);
+            }
+        }
+
+        public static void Multiply(uint[] x, uint[] y, uint[] z)
+        {
+            uint[] tt = Nat192.CreateExt();
+            Nat192.Mul(x, y, tt);
+            Reduce(tt, z);
+        }
+
+        public static void Negate(uint[] x, uint[] z)
+        {
+            if (Nat192.IsZero(x))
+            {
+                Nat192.Zero(z);
+            }
+            else
+            {
+                Nat192.Sub(P, x, z);
+            }
+        }
+
+        public static void Reduce(uint[] tt, uint[] z)
+        {
+            long t06 = tt[6], t07 = tt[7], t08 = tt[8];
+            long t09 = tt[9], t10 = tt[10], t11 = tt[11];
+
+            long cc = 0;
+            cc += (long)tt[0] + t06 + t10;
+            z[0] = (uint)cc;
+            cc >>= 32;
+            cc += (long)tt[1] + t07 + t11;
+            z[1] = (uint)cc;
+            cc >>= 32;
+            cc += (long)tt[2] + t06 + t08 + t10;
+            z[2] = (uint)cc;
+            cc >>= 32;
+            cc += (long)tt[3] + t07 + t09 + t11;
+            z[3] = (uint)cc;
+            cc >>= 32;
+            cc += (long)tt[4] + t08 + t10;
+            z[4] = (uint)cc;
+            cc >>= 32;
+            cc += (long)tt[5] + t09 + t11;
+            z[5] = (uint)cc;
+            cc >>= 32;
+
+            int c = (int)cc;
+            Debug.Assert(c >= 0);
+            while (c > 0)
+            {
+                c += Nat192.Sub(z, P, z);
+            }
+
+            if (z[5] == P5 && Nat192.Gte(z, P))
+            {
+                Nat192.Sub(z, P, z);
+            }
+        }
+
+        public static void Square(uint[] x, uint[] z)
+        {
+            uint[] tt = Nat192.CreateExt();
+            Nat192.Square(x, tt);
+            Reduce(tt, z);
+        }
+
+        public static void SquareN(uint[] x, int n, uint[] z)
+        {
+            Debug.Assert(n > 0);
+
+            uint[] tt = Nat192.CreateExt();
+            Nat192.Square(x, tt);
+            Reduce(tt, z);
+
+            while (--n > 0)
+            {
+                Nat192.Square(z, tt);
+                Reduce(tt, z);
+            }
+        }
+
+        public static void Subtract(uint[] x, uint[] y, uint[] z)
+        {
+            int c = Nat192.Sub(x, y, z);
+            if (c != 0)
+            {
+                Nat192.Add(z, P, z);
+            }
+        }
+
+        public static void SubtractExt(uint[] xx, uint[] yy, uint[] zz)
+        {
+            int c = Nat192.SubExt(xx, yy, zz);
+            if (c != 0)
+            {
+                Nat192.AddExt(zz, PExt, zz);
+            }
+        }
+
+        public static void Twice(uint[] x, uint[] z)
+        {
+            uint c = Nat192.ShiftUpBit(x, 0, z);
+            if (c != 0 || (z[5] == P5 && Nat192.Gte(z, P)))
+            {
+                Nat192.Sub(z, P, z);
+            }
+        }
+    }
+}
diff --git a/crypto/src/math/ec/custom/sec/SecP192R1FieldElement.cs b/crypto/src/math/ec/custom/sec/SecP192R1FieldElement.cs
new file mode 100644
index 000000000..d129ff1ed
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecP192R1FieldElement.cs
@@ -0,0 +1,189 @@
+using System;
+
+using Org.BouncyCastle.Utilities;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecP192R1FieldElement
+        : ECFieldElement
+    {
+        public static readonly BigInteger Q = SecP192R1Curve.q;
+
+        protected internal readonly uint[] x;
+
+        public SecP192R1FieldElement(BigInteger x)
+        {
+            if (x == null || x.SignValue < 0 || x.CompareTo(Q) >= 0)
+                throw new ArgumentException("value invalid for SecP192R1FieldElement", "x");
+
+            this.x = SecP192R1Field.FromBigInteger(x);
+        }
+
+        public SecP192R1FieldElement()
+        {
+            this.x = Nat192.Create();
+        }
+
+        protected internal SecP192R1FieldElement(uint[] x)
+        {
+            this.x = x;
+        }
+
+        public override bool IsZero
+        {
+            get { return Nat192.IsZero(x); }
+        }
+
+        public override bool IsOne
+        {
+            get { return Nat192.IsOne(x); }
+        }
+
+        public override bool TestBitZero()
+        {
+            return Nat192.GetBit(x, 0) == 1;
+        }
+
+        public override BigInteger ToBigInteger()
+        {
+            return Nat192.ToBigInteger(x);
+        }
+
+        public override string FieldName
+        {
+            get { return "SecP192R1Field"; }
+        }
+
+        public override int FieldSize
+        {
+            get { return Q.BitLength; }
+        }
+
+        public override ECFieldElement Add(ECFieldElement b)
+        {
+            uint[] z = Nat192.Create();
+            SecP192R1Field.Add(x, ((SecP192R1FieldElement)b).x, z);
+            return new SecP192R1FieldElement(z);
+        }
+
+        public override ECFieldElement AddOne()
+        {
+            uint[] z = Nat192.Create();
+            SecP192R1Field.AddOne(x, z);
+            return new SecP192R1FieldElement(z);
+        }
+
+        public override ECFieldElement Subtract(ECFieldElement b)
+        {
+            uint[] z = Nat192.Create();
+            SecP192R1Field.Subtract(x, ((SecP192R1FieldElement)b).x, z);
+            return new SecP192R1FieldElement(z);
+        }
+
+        public override ECFieldElement Multiply(ECFieldElement b)
+        {
+            uint[] z = Nat192.Create();
+            SecP192R1Field.Multiply(x, ((SecP192R1FieldElement)b).x, z);
+            return new SecP192R1FieldElement(z);
+        }
+
+        public override ECFieldElement Divide(ECFieldElement b)
+        {
+            //return Multiply(b.Invert());
+            uint[] z = Nat192.Create();
+            Mod.Invert(SecP192R1Field.P, ((SecP192R1FieldElement)b).x, z);
+            SecP192R1Field.Multiply(z, x, z);
+            return new SecP192R1FieldElement(z);
+        }
+
+        public override ECFieldElement Negate()
+        {
+            uint[] z = Nat192.Create();
+            SecP192R1Field.Negate(x, z);
+            return new SecP192R1FieldElement(z);
+        }
+
+        public override ECFieldElement Square()
+        {
+            uint[] z = Nat192.Create();
+            SecP192R1Field.Square(x, z);
+            return new SecP192R1FieldElement(z);
+        }
+
+        public override ECFieldElement Invert()
+        {
+            //return new SecP192R1FieldElement(ToBigInteger().ModInverse(Q));
+            uint[] z = Nat192.Create();
+            Mod.Invert(SecP192R1Field.P, x, z);
+            return new SecP192R1FieldElement(z);
+        }
+
+        /**
+         * return a sqrt root - the routine verifies that the calculation returns the right value - if
+         * none exists it returns null.
+         */
+        public override ECFieldElement Sqrt()
+        {
+            // Raise this element to the exponent 2^190 - 2^62
+
+            uint[] x1 = this.x;
+            if (Nat192.IsZero(x1) || Nat192.IsOne(x1))
+            {
+                return this;
+            }
+
+            uint[] t1 = Nat192.Create();
+            uint[] t2 = Nat192.Create();
+
+            SecP192R1Field.Square(x1, t1);
+            SecP192R1Field.Multiply(t1, x1, t1);
+
+            SecP192R1Field.SquareN(t1, 2, t2);
+            SecP192R1Field.Multiply(t2, t1, t2);
+
+            SecP192R1Field.SquareN(t2, 4, t1);
+            SecP192R1Field.Multiply(t1, t2, t1);
+
+            SecP192R1Field.SquareN(t1, 8, t2);
+            SecP192R1Field.Multiply(t2, t1, t2);
+
+            SecP192R1Field.SquareN(t2, 16, t1);
+            SecP192R1Field.Multiply(t1, t2, t1);
+
+            SecP192R1Field.SquareN(t1, 32, t2);
+            SecP192R1Field.Multiply(t2, t1, t2);
+
+            SecP192R1Field.SquareN(t2, 64, t1);
+            SecP192R1Field.Multiply(t1, t2, t1);
+
+            SecP192R1Field.SquareN(t1, 62, t1);
+            SecP192R1Field.Square(t1, t2);
+
+            return Arrays.AreEqual(x1, t2) ? new SecP192R1FieldElement(t1) : null;
+        }
+
+        public override bool Equals(object obj)
+        {
+            return Equals(obj as SecP192R1FieldElement);
+        }
+
+        public override bool Equals(ECFieldElement other)
+        {
+            return Equals(other as SecP192R1FieldElement);
+        }
+
+        public virtual bool Equals(SecP192R1FieldElement other)
+        {
+            if (this == other)
+                return true;
+            if (null == other)
+                return false;
+            return Arrays.AreEqual(x, other.x);
+        }
+
+        public override int GetHashCode()
+        {
+            return Q.GetHashCode() ^ Arrays.GetHashCode(x);
+        }
+    }
+}
diff --git a/crypto/src/math/ec/custom/sec/SecP192R1Point.cs b/crypto/src/math/ec/custom/sec/SecP192R1Point.cs
new file mode 100644
index 000000000..0dd81f0c7
--- /dev/null
+++ b/crypto/src/math/ec/custom/sec/SecP192R1Point.cs
@@ -0,0 +1,288 @@
+using System;
+
+namespace Org.BouncyCastle.Math.EC.Custom.Sec
+{
+    internal class SecP192R1Point
+        : ECPointBase
+    {
+        /**
+         * Create a point which encodes with point compression.
+         * 
+         * @param curve
+         *            the curve to use
+         * @param x
+         *            affine x co-ordinate
+         * @param y
+         *            affine y co-ordinate
+         * 
+         * @deprecated Use ECCurve.createPoint to construct points
+         */
+        public SecP192R1Point(ECCurve curve, ECFieldElement x, ECFieldElement y)
+            : this(curve, x, y, false)
+        {
+        }
+
+        /**
+         * Create a point that encodes with or without point compresion.
+         * 
+         * @param curve
+         *            the curve to use
+         * @param x
+         *            affine x co-ordinate
+         * @param y
+         *            affine y co-ordinate
+         * @param withCompression
+         *            if true encode with point compression
+         * 
+         * @deprecated per-point compression property will be removed, refer
+         *             {@link #getEncoded(bool)}
+         */
+        public SecP192R1Point(ECCurve curve, ECFieldElement x, ECFieldElement y, bool withCompression)
+            : base(curve, x, y, withCompression)
+        {
+            if ((x == null) != (y == null))
+                throw new ArgumentException("Exactly one of the field elements is null");
+        }
+
+        internal SecP192R1Point(ECCurve curve, ECFieldElement x, ECFieldElement y, ECFieldElement[] zs, bool withCompression)
+            : base(curve, x, y, zs, withCompression)
+        {
+        }
+
+        protected override ECPoint Detach()
+        {
+            return new SecP192R1Point(null, AffineXCoord, AffineYCoord);
+        }
+
+        protected internal override bool CompressionYTilde
+        {
+            get { return this.AffineYCoord.TestBitZero(); }
+        }
+
+        public override ECPoint Add(ECPoint b)
+        {
+            if (this.IsInfinity)
+                return b;
+            if (b.IsInfinity)
+                return this;
+            if (this == b)
+                return Twice();
+
+            ECCurve curve = this.Curve;
+
+            SecP192R1FieldElement X1 = (SecP192R1FieldElement)this.RawXCoord, Y1 = (SecP192R1FieldElement)this.RawYCoord;
+            SecP192R1FieldElement X2 = (SecP192R1FieldElement)b.RawXCoord, Y2 = (SecP192R1FieldElement)b.RawYCoord;
+
+            SecP192R1FieldElement Z1 = (SecP192R1FieldElement)this.RawZCoords[0];
+            SecP192R1FieldElement Z2 = (SecP192R1FieldElement)b.RawZCoords[0];
+
+            uint[] tt1 = Nat192.CreateExt();
+            uint[] tt2 = Nat192.CreateExt();
+            uint[] t3 = Nat192.Create();
+            uint[] t4 = Nat192.Create();
+
+            bool Z1IsOne = Z1.IsOne;
+            uint[] U2, S2;
+            if (Z1IsOne)
+            {
+                U2 = X2.x;
+                S2 = Y2.x;
+            }
+            else
+            {
+                S2 = t3;
+                SecP192R1Field.Square(Z1.x, S2);
+
+                U2 = tt2;
+                SecP192R1Field.Multiply(S2, X2.x, U2);
+
+                SecP192R1Field.Multiply(S2, Z1.x, S2);
+                SecP192R1Field.Multiply(S2, Y2.x, S2);
+            }
+
+            bool Z2IsOne = Z2.IsOne;
+            uint[] U1, S1;
+            if (Z2IsOne)
+            {
+                U1 = X1.x;
+                S1 = Y1.x;
+            }
+            else
+            {
+                S1 = t4;
+                SecP192R1Field.Square(Z2.x, S1);
+
+                U1 = tt1;
+                SecP192R1Field.Multiply(S1, X1.x, U1);
+
+                SecP192R1Field.Multiply(S1, Z2.x, S1);
+                SecP192R1Field.Multiply(S1, Y1.x, S1);
+            }
+
+            uint[] H = Nat192.Create();
+            SecP192R1Field.Subtract(U1, U2, H);
+
+            uint[] R = tt2;
+            SecP192R1Field.Subtract(S1, S2, R);
+
+            // Check if b == this or b == -this
+            if (Nat192.IsZero(H))
+            {
+                if (Nat192.IsZero(R))
+                {
+                    // this == b, i.e. this must be doubled
+                    return this.Twice();
+                }
+
+                // this == -b, i.e. the result is the point at infinity
+                return curve.Infinity;
+            }
+
+            uint[] HSquared = t3;
+            SecP192R1Field.Square(H, HSquared);
+
+            uint[] G = Nat192.Create();
+            SecP192R1Field.Multiply(HSquared, H, G);
+
+            uint[] V = t3;
+            SecP192R1Field.Multiply(HSquared, U1, V);
+
+            Nat192.Mul(S1, G, tt1);
+
+            SecP192R1FieldElement X3 = new SecP192R1FieldElement(t4);
+            SecP192R1Field.Square(R, X3.x);
+            SecP192R1Field.Add(X3.x, G, X3.x);
+            SecP192R1Field.Subtract(X3.x, V, X3.x);
+            SecP192R1Field.Subtract(X3.x, V, X3.x);
+
+            SecP192R1FieldElement Y3 = new SecP192R1FieldElement(G);
+            SecP192R1Field.Subtract(V, X3.x, Y3.x);
+            Nat192.Mul(Y3.x, R, tt2);
+            SecP192R1Field.SubtractExt(tt2, tt1, tt2);
+            SecP192R1Field.Reduce(tt2, Y3.x);
+
+            SecP192R1FieldElement Z3 = new SecP192R1FieldElement(H);
+            if (!Z1IsOne)
+            {
+                SecP192R1Field.Multiply(Z3.x, Z1.x, Z3.x);
+            }
+            if (!Z2IsOne)
+            {
+                SecP192R1Field.Multiply(Z3.x, Z2.x, Z3.x);
+            }
+
+            ECFieldElement[] zs = new ECFieldElement[] { Z3 };
+
+            return new SecP192R1Point(curve, X3, Y3, zs, IsCompressed);
+        }
+
+        public override ECPoint Twice()
+        {
+            if (this.IsInfinity)
+                return this;
+
+            ECCurve curve = this.Curve;
+
+            SecP192R1FieldElement Y1 = (SecP192R1FieldElement)this.RawYCoord;
+            if (Y1.IsZero)
+                return curve.Infinity;
+
+            SecP192R1FieldElement X1 = (SecP192R1FieldElement)this.RawXCoord, Z1 = (SecP192R1FieldElement)this.RawZCoords[0];
+
+            uint[] t1 = Nat192.Create();
+            uint[] t2 = Nat192.Create();
+
+            uint[] Y1Squared = Nat192.Create();
+            SecP192R1Field.Square(Y1.x, Y1Squared);
+
+            uint[] T = Nat192.Create();
+            SecP192R1Field.Square(Y1Squared, T);
+
+            bool Z1IsOne = Z1.IsOne;
+
+            uint[] Z1Squared = Z1.x;
+            if (!Z1IsOne)
+            {
+                Z1Squared = t2;
+                SecP192R1Field.Square(Z1.x, Z1Squared);
+            }
+
+            SecP192R1Field.Subtract(X1.x, Z1Squared, t1);
+
+            uint[] M = t2;
+            SecP192R1Field.Add(X1.x, Z1Squared, M);
+            SecP192R1Field.Multiply(M, t1, M);
+            SecP192R1Field.Twice(M, t1);
+            SecP192R1Field.Add(M, t1, M);
+
+            uint[] S = Y1Squared;
+            SecP192R1Field.Multiply(Y1Squared, X1.x, S);
+            SecP192R1Field.Twice(S, S);
+            SecP192R1Field.Twice(S, S);
+
+            SecP192R1Field.Twice(T, t1);
+            SecP192R1Field.Twice(t1, t1);
+            SecP192R1Field.Twice(t1, t1);
+
+            SecP192R1FieldElement X3 = new SecP192R1FieldElement(T);
+            SecP192R1Field.Square(M, X3.x);
+            SecP192R1Field.Subtract(X3.x, S, X3.x);
+            SecP192R1Field.Subtract(X3.x, S, X3.x);
+
+            SecP192R1FieldElement Y3 = new SecP192R1FieldElement(S);
+            SecP192R1Field.Subtract(S, X3.x, Y3.x);
+            SecP192R1Field.Multiply(Y3.x, M, Y3.x);
+            SecP192R1Field.Subtract(Y3.x, t1, Y3.x);
+
+            SecP192R1FieldElement Z3 = new SecP192R1FieldElement(M);
+            SecP192R1Field.Twice(Y1.x, Z3.x);
+            if (!Z1IsOne)
+            {
+                SecP192R1Field.Multiply(Z3.x, Z1.x, Z3.x);
+            }
+
+            return new SecP192R1Point(curve, X3, Y3, new ECFieldElement[] { Z3 }, IsCompressed);
+        }
+
+        public override ECPoint TwicePlus(ECPoint b)
+        {
+            if (this == b)
+                return ThreeTimes();
+            if (this.IsInfinity)
+                return b;
+            if (b.IsInfinity)
+                return Twice();
+
+            ECFieldElement Y1 = this.RawYCoord;
+            if (Y1.IsZero)
+                return b;
+
+            return Twice().Add(b);
+        }
+
+        public override ECPoint ThreeTimes()
+        {
+            if (this.IsInfinity || this.RawYCoord.IsZero)
+                return this;
+
+            // NOTE: Be careful about recursions between TwicePlus and ThreeTimes
+            return Twice().Add(this);
+        }
+
+        public override ECPoint Subtract(ECPoint b)
+        {
+            if (b.IsInfinity)
+                return this;
+
+            return Add(b.Negate());
+        }
+
+        public override ECPoint Negate()
+        {
+            if (IsInfinity)
+                return this;
+
+            return new SecP192R1Point(Curve, RawXCoord, RawYCoord.Negate(), RawZCoords, IsCompressed);
+        }
+    }
+}