gmaxwell's quiz

import hashlib
import itertools
import time
import math

text = "A8AXWC36F--KF1C-TF-3YW2TG\0-GBM8DOM"
hash = "349cf6e4c59c999dd2df3fbdac8bd840db4a6dc2104b010390850777249f14a7d96fd62a5f828def0315b9c908420c646381fe1b1e67391b3f5bd0588c28fbe0"
#code = "MTGOX-BTC-MYF8W-DWFCA-62GK8-3F31A"

def sha512(s):
    return hashlib.sha512(s + "\n").digest().encode('hex')

def ftime(seconds):
    m, s = divmod(seconds, 60)
    h, m = divmod(m, 60)
    d, h = divmod(h, 24)
    y, d = divmod(d, 365)
    if y > 1:
        return "%d years" % y
    elif d > 1:
        return "%d days" % d
    else:
        return "%02d:%02d:%02d" % (h, m, s)

def bruteforce(text, hash):
    count = 0
    seconds = 0
    start = int(time.time())
#    pt = itertools.permutations("A8AWC36FKF1F3YW2GM8D")
    pt = itertools.permutations("MYF8WDWFCA26GK38F31A")
    digest = hash.decode('hex')
    for p in pt:
        a = "".join(p)
        code = "MTGOX-BTC-" + a[0:5] + "-" + a[5:10] + "-" + a[10:15] + "-" + a[15:20]
        if hashlib.sha512(code + "\n").digest() == digest:
            return code
        count = count + 1
        t = int(time.time()) - start
        if seconds < t:
            seconds = t
            ps = count / seconds
            total = math.factorial(20)
            sec_left = (total - count) / ps
            print code
            print "%d seconds, %d hashes, %d per second, %s left" % (seconds, count, ps, ftime(sec_left))

def ibwt(r):
    """Apply inverse Burrows-Wheeler transform."""
    table = [""] * len(r)  # Make empty table
    for i in range(len(r)):
        table = sorted(r[i] + table[i] for i in range(len(r)))  # Add a column of r
    s = [row for row in table if row.endswith("\0")][0]  # Find the correct row (ending in "\0")
    return s.rstrip("\0")  # Get rid of trailing null character

if __name__ == '__main__':
    code = bruteforce(text, hash)
#    code = ibwt(text)
    print code
    print sha512(code)