Programming Assigment 3

import hashlib import time max_nonce = 2 ** 32 # 4 billion def proof_of_work(header, difficulty_bits): # calculate the difficulty target target = 2 ** (256-difficulty_bits) for nonce in range(max_nonce): # define hash_result based on Problem1.a and Problem1.b # hash_result # check if this is a valid result, below the target 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 = '' # difficulty from 0 to 31 bits for difficulty_bits in range(32): difficulty = 2 ** difficulty_bits print("Difficulty: %ld (%d bits)" % (difficulty, difficulty_bits)) print("Starting search...") # checkpoint the current time start_time = time.time() # make a new block which includes the hash from the previous block # we fake a block of transactions - just a string new_block = 'test block with transactions' + hash_result # find a valid nonce for the new block (hash_result, nonce) = proof_of_work(new_block, difficulty_bits) # checkpoint how long it took to find a result end_time = time.time() elapsed_time = end_time - start_time print("Elapsed Time: %.4f seconds" % elapsed_time) if elapsed_time > 0: # estimate the hashes per second hash_power = float(int(nonce)/elapsed_time) print("Hashing Power: %ld hashes per second" % hash_power) print("\n====================\n")