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| author | Peter Dettman <peter.dettman@bouncycastle.org> | 2014-01-31 18:43:12 +0700 |
|---|---|---|
| committer | Peter Dettman <peter.dettman@bouncycastle.org> | 2014-01-31 18:43:12 +0700 |
| commit | 7118a1a3f987cd82db0243ebcd03e844e73b7ffa (patch) | |
| tree | f03753da78d3531fcf845b70c79091191fb95edf /crypto/src/math/ec/custom/sec/SecP192K1Field.cs | |
| parent | Add custom curves for secp192k1 and secp192r1 (P-192) (diff) | |
| download | BouncyCastle.NET-ed25519-7118a1a3f987cd82db0243ebcd03e844e73b7ffa.tar.xz | |
Improve reduction speed for secp192k1 and secp256k1 custom fields
Diffstat (limited to 'crypto/src/math/ec/custom/sec/SecP192K1Field.cs')
| -rw-r--r-- | crypto/src/math/ec/custom/sec/SecP192K1Field.cs | 11 |
1 files changed, 3 insertions, 8 deletions
diff --git a/crypto/src/math/ec/custom/sec/SecP192K1Field.cs b/crypto/src/math/ec/custom/sec/SecP192K1Field.cs index 30c107c86..9da3c0257 100644 --- a/crypto/src/math/ec/custom/sec/SecP192K1Field.cs +++ b/crypto/src/math/ec/custom/sec/SecP192K1Field.cs @@ -12,7 +12,7 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec 0x00000000, 0xFFFFDC6E, 0xFFFFFFFD, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF, 0xFFFFFFFF }; private const uint PExt11 = 0xFFFFFFFF; private const ulong PInv = 0x00000001000011C9L; - private const uint PInvLow = 0x11C9; + private const uint PInv33 = 0x11C9; public static void Add(uint[] x, uint[] y, uint[] z) { @@ -86,13 +86,8 @@ namespace Org.BouncyCastle.Math.EC.Custom.Sec 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); + ulong c = Nat192.Mul33AddExt(PInv33, tt, 6, tt, 0); + c = Nat192.Mul33DWordAdd(PInv33, c, tt, 0); Debug.Assert(c == 0 || c == 1); |