Competing in the hash|challenge to find the lowest SHA512 hash: http://www.h11e.com/

generate_sha256_multicore.py

import hashlib
from random import random
from multiprocessing import Process, Array
from ctypes import c_char

CPU_CORES = 4

def new_candidate(prev_hash, seed):
    return prev_hash[:32] + seed

def find_lower(lowest, seed):
    # Use previous hash as import for next hash to avoid generating random strings
    # "seed" makes sure processes are working on different namespaces
    candidate = new_candidate(lowest.value, seed)
    while True:
        current_hash = hashlib.sha512(candidate).hexdigest()
        if current_hash < lowest.value:
            lowest.value = current_hash
            print candidate, "->", current_hash

        candidate = new_candidate(current_hash, seed)

def main():
    lowest = Array(c_char, 128, lock=False)
    # Seed with random value so restarts don't search the same sequences
    candidate = str(random())
    lowest.value = hashlib.sha512(candidate).hexdigest()
    print candidate, "->", lowest.value

    processes = [Process(target=find_lower, args=(lowest, str(seed))) for seed in range(CPU_CORES)]

    for process in processes:
        process.start()

    for process in processes:
        process.join()

if __name__ == '__main__':
    main()