ringct: 17% improvement in Borromean signature verification

This commit is contained in:
moneromooo-monero 2018-03-08 00:08:30 +00:00
parent c102c49da5
commit c3e23b2dce
No known key found for this signature in database
GPG key ID: 686F07454D6CEFC3

View file

@ -118,18 +118,31 @@ namespace rct {
}
//see above.
bool verifyBorromean(const boroSig &bb, const key64 P1, const key64 P2) {
bool verifyBorromean(const boroSig &bb, const ge_p3 P1[64], const ge_p3 P2[64]) {
key64 Lv1; key chash, LL;
int ii = 0;
ge_p2 p2;
for (ii = 0 ; ii < 64 ; ii++) {
addKeys2(LL, bb.s0[ii], bb.ee, P1[ii]);
// equivalent of: addKeys2(LL, bb.s0[ii], bb.ee, P1[ii]);
ge_double_scalarmult_base_vartime(&p2, bb.ee.bytes, &P1[ii], bb.s0[ii].bytes);
ge_tobytes(LL.bytes, &p2);
chash = hash_to_scalar(LL);
addKeys2(Lv1[ii], bb.s1[ii], chash, P2[ii]);
// equivalent of: addKeys2(Lv1[ii], bb.s1[ii], chash, P2[ii]);
ge_double_scalarmult_base_vartime(&p2, chash.bytes, &P2[ii], bb.s1[ii].bytes);
ge_tobytes(Lv1[ii].bytes, &p2);
}
key eeComputed = hash_to_scalar(Lv1); //hash function fine
return equalKeys(eeComputed, bb.ee);
}
bool verifyBorromean(const boroSig &bb, const key64 P1, const key64 P2) {
ge_p3 P1_p3[64], P2_p3[64];
for (size_t i = 0 ; i < 64 ; ++i) {
CHECK_AND_ASSERT_MES(ge_frombytes_vartime(&P1_p3[i], P1[i].bytes) == 0, false, "point conv failed");
CHECK_AND_ASSERT_MES(ge_frombytes_vartime(&P2_p3[i], P2[i].bytes) == 0, false, "point conv failed");
}
return verifyBorromean(bb, P1_p3, P2_p3);
}
//Multilayered Spontaneous Anonymous Group Signatures (MLSAG signatures)
//This is a just slghtly more efficient version than the ones described below
@ -336,16 +349,30 @@ namespace rct {
try
{
PERF_TIMER(verRange);
key64 CiH;
ge_p3 CiH[64], asCi[64];
int i = 0;
key Ctmp = identity();
ge_p3 Ctmp_p3 = ge_p3_identity;
for (i = 0; i < 64; i++) {
subKeys(CiH[i], as.Ci[i], H2[i]);
addKeys(Ctmp, Ctmp, as.Ci[i]);
// faster equivalent of:
// subKeys(CiH[i], as.Ci[i], H2[i]);
// addKeys(Ctmp, Ctmp, as.Ci[i]);
ge_cached cached;
ge_p3 p3;
ge_p1p1 p1;
CHECK_AND_ASSERT_MES(ge_frombytes_vartime(&p3, H2[i].bytes) == 0, false, "point conv failed");
ge_p3_to_cached(&cached, &p3);
CHECK_AND_ASSERT_MES(ge_frombytes_vartime(&asCi[i], as.Ci[i].bytes) == 0, false, "point conv failed");
ge_sub(&p1, &asCi[i], &cached);
ge_p3_to_cached(&cached, &asCi[i]);
ge_p1p1_to_p3(&CiH[i], &p1);
ge_add(&p1, &Ctmp_p3, &cached);
ge_p1p1_to_p3(&Ctmp_p3, &p1);
}
key Ctmp;
ge_p3_tobytes(Ctmp.bytes, &Ctmp_p3);
if (!equalKeys(C, Ctmp))
return false;
if (!verifyBorromean(as.asig, as.Ci, CiH))
if (!verifyBorromean(as.asig, asCi, CiH))
return false;
return true;
}