diff options
Diffstat (limited to 'include/mcl/bn.hpp')
| -rw-r--r-- | include/mcl/bn.hpp | 18 |
1 files changed, 17 insertions, 1 deletions
diff --git a/include/mcl/bn.hpp b/include/mcl/bn.hpp index 38f3f8d..8e9a9c6 100644 --- a/include/mcl/bn.hpp +++ b/include/mcl/bn.hpp @@ -414,6 +414,9 @@ struct MapTo { #endif #endif } + /* + 1.2~1.4 times faster than calBN + */ template<class G, class F> void naiveMapTo(G& P, const F& t) const { @@ -480,6 +483,10 @@ struct MapTo { z_ = z; // cofactor for G1 cofactor_ = (z - 1) * (z - 1) / 3; + bool b = Fp::squareRoot(c1_, -3); + assert(b); + (void)b; + c2_ = (c1_ - 1) / 2; } void init(const mpz_class& cofactor, const mpz_class &z, bool isBN, int curveType = -1) { @@ -494,8 +501,13 @@ struct MapTo { { if (isBN_) { if (!calcBN<G1, Fp>(P, t)) return false; + // no subgroup } else { +#ifdef MCL_USE_OLD_MAPTO_FOR_BLS12 naiveMapTo<G1, Fp>(P, t); +#else + if (!calcBN<G1, Fp>(P, t)) return false; +#endif mulByCofactorBLS12(P, P); } assert(P.isValid()); @@ -510,7 +522,11 @@ struct MapTo { if (!calcBN<G2, Fp2>(P, t)) return false; mulByCofactorBN(P, P); } else { - naiveMapTo<G2, Fp2>(P, t); +#ifdef MCL_USE_OLD_MAPTO_FOR_BLS12 + naiveMapTo<G1, Fp>(P, t); +#else + if (!calcBN<G2, Fp2>(P, t)) return false; +#endif mulByCofactorBLS12(P, P); } assert(P.isValid()); |