mirror of
https://github.com/henrydcase/nobs.git
synced 2024-11-25 16:41:32 +00:00
Kris Kwiatkowski
7efbbf4745
Implementation of Commutative Supersingular Isogeny Diffie Hellman, based on "A faster way to CSIDH" paper (2018/782). * For fast isogeny calculation, implementation converts a curve from Montgomery to Edwards. All calculations are done on Edwards curve and then converted back to Montgomery. * As multiplication in a field Fp511 is most expensive operation the implementation contains multiple multiplications. It has most performant, assembly implementation which uses BMI2 and ADOX/ADCX instructions for modern CPUs. It also contains slower implementation which will run on older CPUs * Benchmarks (Intel SkyLake): BenchmarkGeneratePrivate 6459 172213 ns/op 0 B/op 0 allocs/op BenchmarkGenerateKeyPair 25 45800356 ns/op 0 B/op 0 allocs/op BenchmarkValidate 297 3915983 ns/op 0 B/op 0 allocs/op BenchmarkValidateRandom 184683 6231 ns/op 0 B/op 0 allocs/op BenchmarkValidateGenerated 25 48481306 ns/op 0 B/op 0 allocs/op BenchmarkDerive 19 60928763 ns/op 0 B/op 0 allocs/op BenchmarkDeriveGenerated 8 137342421 ns/op 0 B/op 0 allocs/op BenchmarkXMul 2311 494267 ns/op 1 B/op 0 allocs/op BenchmarkXAdd 2396754 501 ns/op 0 B/op 0 allocs/op BenchmarkXDbl 2072690 571 ns/op 0 B/op 0 allocs/op BenchmarkIsom 78004 15171 ns/op 0 B/op 0 allocs/op BenchmarkFp512Sub 224635152 5.33 ns/op 0 B/op 0 allocs/op BenchmarkFp512Mul 246633255 4.90 ns/op 0 B/op 0 allocs/op BenchmarkCSwap 233228547 5.10 ns/op 0 B/op 0 allocs/op BenchmarkAddRdc 87348240 12.6 ns/op 0 B/op 0 allocs/op BenchmarkSubRdc 95112787 11.7 ns/op 0 B/op 0 allocs/op BenchmarkModExpRdc 25436 46878 ns/op 0 B/op 0 allocs/op BenchmarkMulBmiAsm 19527573 60.1 ns/op 0 B/op 0 allocs/op BenchmarkMulGeneric 7117650 164 ns/op 0 B/op 0 allocs/op * Go code has very similar performance when compared to C implementation. Results from sidh_torturer (4e2996e12d68364761064341cbe1d1b47efafe23) github.com:henrydcase/sidh-torture/csidh | TestName |Go | C | |------------------|----------|----------| |TestSharedSecret | 57.95774 | 57.91092 | |TestKeyGeneration | 62.23614 | 58.12980 | |TestSharedSecret | 55.28988 | 57.23132 | |TestKeyGeneration | 61.68745 | 58.66396 | |TestSharedSecret | 63.19408 | 58.64774 | |TestKeyGeneration | 62.34022 | 61.62539 | |TestSharedSecret | 62.85453 | 68.74503 | |TestKeyGeneration | 52.58518 | 58.40115 | |TestSharedSecret | 50.77081 | 61.91699 | |TestKeyGeneration | 59.91843 | 61.09266 | |TestSharedSecret | 59.97962 | 62.98151 | |TestKeyGeneration | 64.57525 | 56.22863 | |TestSharedSecret | 56.40521 | 55.77447 | |TestKeyGeneration | 67.85850 | 58.52604 | |TestSharedSecret | 60.54290 | 65.14052 | |TestKeyGeneration | 65.45766 | 58.42823 | On average Go implementation is 2% faster.
51 lines
1.1 KiB
Go
51 lines
1.1 KiB
Go
// +build amd64,!noasm
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package csidh
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import "math/bits"
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//go:noescape
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func mul512(a, b *fp, c uint64)
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//go:noescape
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func mul576(a *[9]uint64, b *fp, c uint64)
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//go:noescape
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func cswap512(x, y *fp, choice uint8)
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//go:noescape
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func mulBmiAsm(res, x, y *fp)
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// mulRdc performs montgomery multiplication r = x * y mod P.
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// Returned result r is already reduced and in Montgomery domain.
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func mulRdc(r, x, y *fp) {
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var t fp
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var c uint64
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if hasADXandBMI2 {
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mulBmiAsm(r, x, y)
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} else {
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mulGeneric(r, x, y)
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}
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// if p <= r < 2p then r = r-p
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t[0], c = bits.Sub64(r[0], p[0], 0)
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t[1], c = bits.Sub64(r[1], p[1], c)
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t[2], c = bits.Sub64(r[2], p[2], c)
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t[3], c = bits.Sub64(r[3], p[3], c)
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t[4], c = bits.Sub64(r[4], p[4], c)
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t[5], c = bits.Sub64(r[5], p[5], c)
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t[6], c = bits.Sub64(r[6], p[6], c)
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t[7], c = bits.Sub64(r[7], p[7], c)
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var w = 0 - c
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r[0] = ctPick64(w, r[0], t[0])
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r[1] = ctPick64(w, r[1], t[1])
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r[2] = ctPick64(w, r[2], t[2])
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r[3] = ctPick64(w, r[3], t[3])
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r[4] = ctPick64(w, r[4], t[4])
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r[5] = ctPick64(w, r[5], t[5])
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r[6] = ctPick64(w, r[6], t[6])
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r[7] = ctPick64(w, r[7], t[7])
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}
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