return (best_keyword, best_wrap_alphabet), best_fit
def keyword_break_mp(message, wordlist=keywords, fitness=Pletters,
- chunksize=500):
+ number_of_solutions=1, chunksize=500):
"""Breaks a keyword substitution cipher using a dictionary and
frequency analysis
'keyword decipherment', 'elephant', KeywordWrapAlphabet.from_last), \
wordlist=['cat', 'elephant', 'kangaroo']) # doctest: +ELLIPSIS
(('elephant', <KeywordWrapAlphabet.from_last: 2>), -52.834575011...)
+ >>> keyword_break_mp(keyword_encipher('this is a test message for the ' \
+ 'keyword decipherment', 'elephant', KeywordWrapAlphabet.from_last), \
+ wordlist=['cat', 'elephant', 'kangaroo'], \
+ number_of_solutions=2) # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
+ [(('elephant', <KeywordWrapAlphabet.from_last: 2>), -52.834575011...),
+ (('elephant', <KeywordWrapAlphabet.from_largest: 3>), -52.834575011...)]
"""
with Pool() as pool:
helper_args = [(message, word, wrap, fitness)
# Gotcha: the helper function here needs to be defined at the top level
# (limitation of Pool.starmap)
breaks = pool.starmap(keyword_break_worker, helper_args, chunksize)
- return max(breaks, key=lambda k: k[1])
+ if number_of_solutions == 1:
+ return max(breaks, key=lambda k: k[1])
+ else:
+ return sorted(breaks, key=lambda k: k[1], reverse=True)[:number_of_solutions]
def keyword_break_worker(message, keyword, wrap_alphabet, fitness):
plaintext = keyword_decipher(message, keyword, wrap_alphabet)