From bd6879ac518431174a490ba42f7e6e822dcb3ee1 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?P=C3=A9ter=20Szil=C3=A1gyi?= Date: Mon, 5 Mar 2018 14:33:45 +0200 Subject: core/vm, crypto/bn256: switch over to cloudflare library (#16203) * core/vm, crypto/bn256: switch over to cloudflare library * crypto/bn256: unmarshal constraint + start pure go impl * crypto/bn256: combo cloudflare and google lib * travis: drop 386 test job --- crypto/bn256/google/example_test.go | 43 +++++++++++++++++++++++++++++++++++++ 1 file changed, 43 insertions(+) create mode 100644 crypto/bn256/google/example_test.go (limited to 'crypto/bn256/google/example_test.go') diff --git a/crypto/bn256/google/example_test.go b/crypto/bn256/google/example_test.go new file mode 100644 index 000000000..b2d19807a --- /dev/null +++ b/crypto/bn256/google/example_test.go @@ -0,0 +1,43 @@ +// Copyright 2012 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package bn256 + +import ( + "crypto/rand" +) + +func ExamplePair() { + // This implements the tripartite Diffie-Hellman algorithm from "A One + // Round Protocol for Tripartite Diffie-Hellman", A. Joux. + // http://www.springerlink.com/content/cddc57yyva0hburb/fulltext.pdf + + // Each of three parties, a, b and c, generate a private value. + a, _ := rand.Int(rand.Reader, Order) + b, _ := rand.Int(rand.Reader, Order) + c, _ := rand.Int(rand.Reader, Order) + + // Then each party calculates g₁ and g₂ times their private value. + pa := new(G1).ScalarBaseMult(a) + qa := new(G2).ScalarBaseMult(a) + + pb := new(G1).ScalarBaseMult(b) + qb := new(G2).ScalarBaseMult(b) + + pc := new(G1).ScalarBaseMult(c) + qc := new(G2).ScalarBaseMult(c) + + // Now each party exchanges its public values with the other two and + // all parties can calculate the shared key. + k1 := Pair(pb, qc) + k1.ScalarMult(k1, a) + + k2 := Pair(pc, qa) + k2.ScalarMult(k2, b) + + k3 := Pair(pa, qb) + k3.ScalarMult(k3, c) + + // k1, k2 and k3 will all be equal. +} -- cgit v1.2.3