区块链共识机制 —— PoW共识的Python实现

原始实现（python2 版本）

https://github.com/santisiri/proof-of-work

依据python3特性改进后：

#!/usr/bin/env python
# example of proof of work algorithm

import hashlib
import time

max_nonce = 2 ** 32 # 4 billion

def proof_of_work(header, difficulty_bits):

    target = 2 ** (256-difficulty_bits)
    for nonce in range(max_nonce):
        hash_result = hashlib.sha256((str(header)+str(nonce)).encode("utf-8")).hexdigest()
        if int(hash_result, 16) < target:
            print( "Success with nonce %d" % nonce )
            print( "Hash is %s" % hash_result )
            return (hash_result, nonce)

    print( "Failed after %d (max_nonce) tries" % nonce )
    return nonce

if __name__ == '__main__':

    nonce = 0
    hash_result = ''

    for difficulty_bits in range(32):

        difficulty = 2 ** difficulty_bits

        print( "" )
        print( "Difficulty: %ld (%d bits)" % (difficulty, difficulty_bits) )

        print( "Starting search..." )

        start_time = time.time()

        new_block = 'test block with transactions' + hash_result

        (hash_result, nonce) = proof_of_work(new_block, difficulty_bits)

        end_time = time.time()

        elapsed_time = end_time - start_time

        print( "Elapsed time: %.4f seconds" % elapsed_time )

        if elapsed_time > 0:

            hash_power = float(int(nonce)/elapsed_time)
            print( "Hashing power: %ld hashes per second" % hash_power )

运行结果：

注：

具体原理不知。

====================================

参考：

简述目前相对成熟的区块链共识算法

====================================