This commit is a preparation for the upcoming metropolis hardfork. It prepares the state, core and vm packages such that integration with metropolis becomes less of a hassle. * Difficulty calculation requires header instead of individual parameters * statedb.StartRecord renamed to statedb.Prepare and added Finalise method required by metropolis, which removes unwanted accounts from the state (i.e. selfdestruct) * State keeps record of destructed objects (in addition to dirty objects) * core/vm pre-compiles may now return errors * core/vm pre-compiles gas check now take the full byte slice as argument instead of just the size * core/vm now keeps several hard-fork instruction tables instead of a single instruction table and removes the need for hard-fork checks in the instructions * core/vm contains a empty restruction function which is added in preparation of metropolis write-only mode operations * Adds the bn256 curve * Adds and sets the metropolis chain config block parameters (2^64-1)
		
			
				
	
	
		
			44 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
			
		
		
	
	
			44 lines
		
	
	
		
			1.1 KiB
		
	
	
	
		
			Go
		
	
	
	
	
	
// 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.
 | 
						|
}
 |