From 1b867e7f4087378a04a0b94d720d3bed8505e245 Mon Sep 17 00:00:00 2001 From: moneromooo-monero Date: Thu, 24 May 2018 20:14:09 +0100 Subject: [PATCH] precalc the ge_p3 representation of H --- src/crypto/crypto-ops-data.c | 6 ++++++ src/crypto/crypto-ops.h | 1 + src/ringct/bulletproofs.cc | 22 +++++++++++----------- src/ringct/rctOps.cpp | 4 +--- tests/unit_tests/ringct.cpp | 7 +++++++ 5 files changed, 26 insertions(+), 14 deletions(-) diff --git a/src/crypto/crypto-ops-data.c b/src/crypto/crypto-ops-data.c index 4ff4310de..1f77513ca 100644 --- a/src/crypto/crypto-ops-data.c +++ b/src/crypto/crypto-ops-data.c @@ -871,3 +871,9 @@ const fe fe_fffb2 = {8166131, -6741800, -17040804, 3154616, 21461005, 1466302, - const fe fe_fffb3 = {-13620103, 14639558, 4532995, 7679154, 16815101, -15883539, -22863840, -14813421, 13716513, -6477756}; /* sqrt(-sqrt(-1) * A * (A + 2)) */ const fe fe_fffb4 = {-21786234, -12173074, 21573800, 4524538, -4645904, 16204591, 8012863, -8444712, 3212926, 6885324}; /* sqrt(sqrt(-1) * A * (A + 2)) */ const ge_p3 ge_p3_identity = { {0}, {1, 0}, {1, 0}, {0} }; +const ge_p3 ge_p3_H = { + {7329926, -15101362, 31411471, 7614783, 27996851, -3197071, -11157635, -6878293, 466949, -7986503}, + {5858699, 5096796, 21321203, -7536921, -5553480, -11439507, -5627669, 15045946, 19977121, 5275251}, + {1, 0, 0, 0, 0, 0, 0, 0, 0, 0}, + {23443568, -5110398, -8776029, -4345135, 6889568, -14710814, 7474843, 3279062, 14550766, -7453428} +}; diff --git a/src/crypto/crypto-ops.h b/src/crypto/crypto-ops.h index dc3c60794..52854889f 100644 --- a/src/crypto/crypto-ops.h +++ b/src/crypto/crypto-ops.h @@ -140,6 +140,7 @@ extern const fe fe_fffb2; extern const fe fe_fffb3; extern const fe fe_fffb4; extern const ge_p3 ge_p3_identity; +extern const ge_p3 ge_p3_H; void ge_fromfe_frombytes_vartime(ge_p2 *, const unsigned char *); void sc_0(unsigned char *); void sc_reduce32(unsigned char *); diff --git a/src/ringct/bulletproofs.cc b/src/ringct/bulletproofs.cc index dc5918738..884c99537 100644 --- a/src/ringct/bulletproofs.cc +++ b/src/ringct/bulletproofs.cc @@ -521,8 +521,8 @@ Bulletproof bulletproof_PROVE(const rct::key &sv, const rct::key &gamma) // PAPER LINES 47-48 rct::key tau1 = rct::skGen(), tau2 = rct::skGen(); - rct::key T1 = rct::addKeys(rct::scalarmultKey(rct::H, t1), rct::scalarmultBase(tau1)); - rct::key T2 = rct::addKeys(rct::scalarmultKey(rct::H, t2), rct::scalarmultBase(tau2)); + rct::key T1 = rct::addKeys(rct::scalarmultH(t1), rct::scalarmultBase(tau1)); + rct::key T2 = rct::addKeys(rct::scalarmultH(t2), rct::scalarmultBase(tau2)); // PAPER LINES 49-51 rct::key x = hash_cache_mash(hash_cache, z, T1, T2); @@ -592,10 +592,10 @@ Bulletproof bulletproof_PROVE(const rct::key &sv, const rct::key &gamma) // PAPER LINES 18-19 L[round] = vector_exponent_custom(slice(Gprime, nprime, Gprime.size()), slice(Hprime, 0, nprime), slice(aprime, 0, nprime), slice(bprime, nprime, bprime.size())); sc_mul(tmp.bytes, cL.bytes, x_ip.bytes); - rct::addKeys(L[round], L[round], rct::scalarmultKey(rct::H, tmp)); + rct::addKeys(L[round], L[round], rct::scalarmultH(tmp)); R[round] = vector_exponent_custom(slice(Gprime, 0, nprime), slice(Hprime, nprime, Hprime.size()), slice(aprime, nprime, aprime.size()), slice(bprime, 0, nprime)); sc_mul(tmp.bytes, cR.bytes, x_ip.bytes); - rct::addKeys(R[round], R[round], rct::scalarmultKey(rct::H, tmp)); + rct::addKeys(R[round], R[round], rct::scalarmultH(tmp)); // PAPER LINES 21-22 w[round] = hash_cache_mash(hash_cache, L[round], R[round]); @@ -764,8 +764,8 @@ Bulletproof bulletproof_PROVE(const rct::keyV &sv, const rct::keyV &gamma) // PAPER LINES 47-48 rct::key tau1 = rct::skGen(), tau2 = rct::skGen(); - rct::key T1 = rct::addKeys(rct::scalarmultKey(rct::H, t1), rct::scalarmultBase(tau1)); - rct::key T2 = rct::addKeys(rct::scalarmultKey(rct::H, t2), rct::scalarmultBase(tau2)); + rct::key T1 = rct::addKeys(rct::scalarmultH(t1), rct::scalarmultBase(tau1)); + rct::key T2 = rct::addKeys(rct::scalarmultH(t2), rct::scalarmultBase(tau2)); // PAPER LINES 49-51 rct::key x = hash_cache_mash(hash_cache, z, T1, T2); @@ -842,10 +842,10 @@ Bulletproof bulletproof_PROVE(const rct::keyV &sv, const rct::keyV &gamma) // PAPER LINES 18-19 L[round] = vector_exponent_custom(slice(Gprime, nprime, Gprime.size()), slice(Hprime, 0, nprime), slice(aprime, 0, nprime), slice(bprime, nprime, bprime.size())); sc_mul(tmp.bytes, cL.bytes, x_ip.bytes); - rct::addKeys(L[round], L[round], rct::scalarmultKey(rct::H, tmp)); + rct::addKeys(L[round], L[round], rct::scalarmultH(tmp)); R[round] = vector_exponent_custom(slice(Gprime, 0, nprime), slice(Hprime, nprime, Hprime.size()), slice(aprime, nprime, aprime.size()), slice(bprime, 0, nprime)); sc_mul(tmp.bytes, cR.bytes, x_ip.bytes); - rct::addKeys(R[round], R[round], rct::scalarmultKey(rct::H, tmp)); + rct::addKeys(R[round], R[round], rct::scalarmultH(tmp)); // PAPER LINES 21-22 w[round] = hash_cache_mash(hash_cache, L[round], R[round]); @@ -964,7 +964,7 @@ bool bulletproof_VERIFY(const std::vector &proofs) sc_muladd(tmp.bytes, z.bytes, ip1y.bytes, k.bytes); std::vector multiexp_data; multiexp_data.reserve(3+proof.V.size()); - multiexp_data.emplace_back(tmp, rct::H); + multiexp_data.emplace_back(tmp, ge_p3_H); for (size_t j = 0; j < proof.V.size(); j++) { multiexp_data.emplace_back(zpow[j+2], proof.V[j]); @@ -980,7 +980,7 @@ bool bulletproof_VERIFY(const std::vector &proofs) { PERF_TIMER_START_BP(VERIFY_line_61rl_old); sc_muladd(tmp.bytes, z.bytes, ip1y.bytes, k.bytes); - L61Right = rct::scalarmultKey(rct::H, tmp); + L61Right = rct::scalarmultH(tmp); ge_p3 L61Right_p3; CHECK_AND_ASSERT_THROW_MES(ge_frombytes_vartime(&L61Right_p3, L61Right.bytes) == 0, "ge_frombytes_vartime failed"); for (size_t j = 0; j+1 < proof.V.size(); j += 2) @@ -1118,7 +1118,7 @@ bool bulletproof_VERIFY(const std::vector &proofs) sc_sub(tmp.bytes, rct::zero().bytes, z1.bytes); rct::addKeys(Y, Y, rct::scalarmultBase(tmp)); rct::addKeys(Y, Y, Z2); - rct::addKeys(Y, Y, rct::scalarmultKey(rct::H, z3)); + rct::addKeys(Y, Y, rct::scalarmultH(z3)); std::vector multiexp_data; multiexp_data.reserve(2 * maxMN); diff --git a/src/ringct/rctOps.cpp b/src/ringct/rctOps.cpp index 50693bad7..fe0ad8747 100644 --- a/src/ringct/rctOps.cpp +++ b/src/ringct/rctOps.cpp @@ -193,10 +193,8 @@ namespace rct { //Computes aH where H= toPoint(cn_fast_hash(G)), G the basepoint key scalarmultH(const key & a) { - ge_p3 A; ge_p2 R; - CHECK_AND_ASSERT_THROW_MES_L1(ge_frombytes_vartime(&A, H.bytes) == 0, "ge_frombytes_vartime failed at "+boost::lexical_cast(__LINE__)); - ge_scalarmult(&R, a.bytes, &A); + ge_scalarmult(&R, a.bytes, &ge_p3_H); key aP; ge_tobytes(aP.bytes, &R); return aP; diff --git a/tests/unit_tests/ringct.cpp b/tests/unit_tests/ringct.cpp index d4e942176..360529b9e 100644 --- a/tests/unit_tests/ringct.cpp +++ b/tests/unit_tests/ringct.cpp @@ -1086,6 +1086,13 @@ TEST(ringct, zeroCommmit) ASSERT_EQ(z, manual); } +TEST(ringct, H) +{ + ge_p3 p3; + ASSERT_EQ(ge_frombytes_vartime(&p3, rct::H.bytes), 0); + ASSERT_EQ(memcmp(&p3, &ge_p3_H, sizeof(ge_p3)), 0); +} + TEST(ringct, aggregated) { static const size_t N_PROOFS = 16;