From 572fa8d81688d7e335ec55352ea382f736f22a30 Mon Sep 17 00:00:00 2001
From: MITSUNARI Shigeo <herumi@nifty.com>
Date: Sat, 17 Aug 2019 18:21:16 +0900
Subject: [PATCH] add millerLoopVec

---
 include/mcl/bn.hpp | 19 +++++++++++++++++++
 test/bn_test.cpp   | 23 +++++++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/include/mcl/bn.hpp b/include/mcl/bn.hpp
index 147f8bb..53a456f 100644
--- a/include/mcl/bn.hpp
+++ b/include/mcl/bn.hpp
@@ -1900,6 +1900,25 @@ inline void precomputedMillerLoop2mixed(Fp12& f, const G1& P1, const G2& Q1, con
 	precomputedMillerLoop2mixed(f, P1, Q1, P2, Q2coeff.data());
 }
 #endif
+
+/*
+	f = prod_{i=0}^{n-1} millerLoop(Pvec[i], Qvec[i])
+*/
+inline void millerLoopVec(Fp12& f, const G1* Pvec, const G2* Qvec, size_t n)
+{
+	if (n == 0) {
+		f = 1;
+		return;
+	}
+	millerLoop(f, Pvec[0], Qvec[0]);
+	for (size_t i = 1; i < n; i++) {
+		Fp12 g;
+		millerLoop(g, Pvec[i], Qvec[i]);
+		f *= g;
+	}
+}
+
+
 inline void mapToG1(bool *pb, G1& P, const Fp& x) { *pb = BN::param.mapTo.calcG1(P, x); }
 inline void mapToG2(bool *pb, G2& P, const Fp2& x) { *pb = BN::param.mapTo.calcG2(P, x); }
 #ifndef CYBOZU_DONT_USE_EXCEPTION
diff --git a/test/bn_test.cpp b/test/bn_test.cpp
index 071ec70..b66cad8 100644
--- a/test/bn_test.cpp
+++ b/test/bn_test.cpp
@@ -249,6 +249,28 @@ void testMillerLoop2(const G1& P1, const G2& Q1)
 	CYBOZU_TEST_EQUAL(e2, e3);
 }
 
+void testMillerLoopVec()
+{
+	const size_t n = 8;
+	G1 Pvec[n];
+	G2 Qvec[n];
+	char c = 'a';
+	for (size_t i = 0; i < n; i++) {
+		hashAndMapToG1(Pvec[i], &c, 1);
+		hashAndMapToG2(Qvec[i], &c, 1);
+		c++;
+	}
+	Fp12 f1, f2;
+	f1 = 1;
+	for (size_t i = 0; i < n; i++) {
+		Fp12 e;
+		millerLoop(e, Pvec[i], Qvec[i]);
+		f1 *= e;
+	}
+	millerLoopVec(f2, Pvec, Qvec, n);
+	CYBOZU_TEST_EQUAL(f1, f2);
+}
+
 void testPairing(const G1& P, const G2& Q, const char *eStr)
 {
 	Fp12 e1;
@@ -378,6 +400,7 @@ CYBOZU_TEST_AUTO(naive)
 		testPairing(P, Q, ts.e);
 		testPrecomputed(P, Q);
 		testMillerLoop2(P, Q);
+		testMillerLoopVec();
 		testBench(P, Q);
 		benchAddDblG1();
 		benchAddDblG2();