add BLS signature sample

2 files changed, 67 insertions, 1 deletions

diff --git a/Makefile b/Makefile
index f15c34c..f9fe9bd 100644
--- a/Makefile
+++ b/Makefile
@@ -14,7 +14,7 @@ ifeq ($(CPU),x86-64)
     TEST_SRC+=fp_generator_test.cpp
   endif
 endif
-SAMPLE_SRC=bench.cpp ecdh.cpp random.cpp rawbench.cpp vote.cpp pairing.cpp large.cpp tri-dh.cpp
+SAMPLE_SRC=bench.cpp ecdh.cpp random.cpp rawbench.cpp vote.cpp pairing.cpp large.cpp tri-dh.cpp bls_sig.cpp
 
 ifneq ($(MCL_MAX_BIT_SIZE),)
   CFLAGS+=-DMCL_MAX_BIT_SIZE=$(MCL_MAX_BIT_SIZE)
diff --git a/sample/bls_sig.cpp b/sample/bls_sig.cpp
new file mode 100644
index 0000000..9098185
--- /dev/null
+++ b/sample/bls_sig.cpp
@@ -0,0 +1,66 @@
+/**
+	@file
+	@brief a sample of BLS signature
+	see https://github.com/herumi/bls
+	@author MITSUNARI Shigeo(@herumi)
+	@license modified new BSD license
+	http://opensource.org/licenses/BSD-3-Clause
+
+*/
+#include <mcl/bn256.hpp>
+
+#if CYBOZU_CPP_VERSION >= CYBOZU_CPP_VERSION_CPP11
+#include <random>
+std::random_device g_rg;
+#else
+#include <cybozu/random_generator.hpp>
+cybozu::RandomGenerator g_rg;
+#endif
+
+using namespace mcl::bn256;
+
+void Hash(G1& P, const std::string& m)
+{
+	Fp t;
+	t.setMsg(m);
+	BN::mapToG1(P, t);
+}
+
+int main(int argc, char *argv[])
+{
+	std::string m = argc == 1 ? "hello mcl" : argv[1];
+
+	// setup parameter
+	bn256init();
+	G1 P(-1, 1);
+	G2 Q;
+	BN::mapToG2(Q, 1);
+
+	// generate secret key and public key
+	Fr s;
+	s.setRand(g_rg);
+	std::cout << "secret key " << s << std::endl;
+	G2 pub;
+	G2::mul(pub, Q, s); // pub = sQ
+	std::cout << "public key " << pub << std::endl;
+
+	// sign
+	G1 sign;
+	{
+		G1 Hm;
+		Hash(Hm, m);
+		G1::mul(sign, Hm, s); // sign = s H(m)
+	}
+	std::cout << "msg " << m << std::endl;
+	std::cout << "sign " << sign << std::endl;
+
+	// verify
+	{
+		Fp12 e1, e2;
+		G1 Hm;
+		Hash(Hm, m);
+		BN::pairing(e1, sign, Q); // e1 = e(sign, Q)
+		BN::pairing(e2, Hm, pub); // e2 = e(Hm, sQ)
+		std::cout << "verify " << (e1 == e2 ? "ok" : "ng") << std::endl;
+	}
+}