import matplotlib.pyplot as plt
-logging.basicConfig(filename="cipher.log", level=logging.INFO)
-logger = logging.getLogger(__name__)
-# logger.setLevel(logging.WARNING)
+# logging.basicConfig(filename="cipher.log", level=logging.INFO)
+# logger = logging.getLogger(__name__)
+
+logger = logging.getLogger('cipherbreak')
+logger.setLevel(logging.WARNING)
# logger.setLevel(logging.INFO)
# logger.setLevel(logging.DEBUG)
+# create the logging file handler
+fh = logging.FileHandler("cipher.log")
+formatter = logging.Formatter('%(asctime)s - %(name)s - %(levelname)s - %(message)s')
+fh.setFormatter(formatter)
+
+# add handler to logger object
+logger.addHandler(fh)
+
+
from cipher import *
from language_models import *
>>> vigenere_keyword_break_mp(vigenere_encipher(sanitise('this is a test ' \
'message for the vigenere decipherment'), 'cat'), \
wordlist=['cat', 'elephant', 'kangaroo']) # doctest: +ELLIPSIS
- ('cat', -52.947271216...)
+ ('cat', -52.9472712...)
"""
with Pool() as pool:
helper_args = [(message, word, fitness)
"certain that the theft has been discovered and that I will " \
"be caught. The SS officer visits less often now that he is " \
"sure"), 'florence')) # doctest: +ELLIPSIS
- ('florence', -307.5473096791...)
+ ('florence', -307.5473096...)
"""
def worker(message, key_length, fitness):
splits = every_nth(sanitised_message, key_length)
- key = cat([chr(caesar_break(s)[0] + ord('a')) for s in splits])
+ key = cat([unpos(caesar_break(s)[0]) for s in splits])
plaintext = vigenere_decipher(message, key)
fit = fitness(plaintext)
return key, fit
return max(results, key=lambda k: k[1])
+def beaufort_sub_break(message, fitness=Pletters):
+ """Breaks one chunk of a Beaufort cipher with frequency analysis
+
+ >>> beaufort_sub_break('samwpplggnnmmyaazgympjapopnwiywwomwspgpjmefwmawx' \
+ 'jafjhxwwwdigxshnlywiamhyshtasxptwueahhytjwsn') # doctest: +ELLIPSIS
+ (0, -117.4492...)
+ >>> beaufort_sub_break('eyprzjjzznxymrygryjqmqhznjrjjapenejznawngnnezgza' \
+ 'dgndknaogpdjneadadazlhkhxkryevrronrmdjnndjlo') # doctest: +ELLIPSIS
+ (17, -114.9598...)
+ """
+ best_shift = 0
+ best_fit = float('-inf')
+ for key in range(26):
+ plaintext = [unpos(key - pos(l)) for l in message]
+ fit = fitness(plaintext)
+ logger.debug('Beaufort sub break attempt using key {0} gives fit of {1} '
+ 'and decrypt starting: {2}'.format(key, fit,
+ plaintext[:50]))
+ if fit > best_fit:
+ best_fit = fit
+ best_key = key
+ logger.info('Beaufort sub break best fit: key {0} gives fit of {1} and '
+ 'decrypt starting: {2}'.format(best_key, best_fit,
+ cat([unpos(best_key - pos(l)) for l in message[:50]])))
+ return best_key, best_fit
+
+
def beaufort_frequency_break(message, max_key_length=20, fitness=Pletters):
"""Breaks a Beaufort cipher with frequency analysis
('florence', -307.5473096791...)
"""
def worker(message, key_length, fitness):
- splits = every_nth(sanitised_message, key_length)
- key = cat([chr(-caesar_break(s)[0] % 26 + ord('a'))
- for s in splits])
+ splits = every_nth(message, key_length)
+ key = cat([unpos(beaufort_sub_break(s)[0]) for s in splits])
plaintext = beaufort_decipher(message, key)
fit = fitness(plaintext)
return key, fit
sanitised_message = sanitise(message)
+ results = starmap(worker, [(sanitised_message, i, fitness)
+ for i in range(1, max_key_length+1)])
+ return max(results, key=lambda k: k[1])
+
+
+def beaufort_variant_frequency_break(message, max_key_length=20, fitness=Pletters):
+ """Breaks a Beaufort cipher with frequency analysis
+
+ >>> beaufort_variant_frequency_break(beaufort_variant_encipher(sanitise("It is time to " \
+ "run. She is ready and so am I. I stole Daniel's pocketbook this " \
+ "afternoon when he left his jacket hanging on the easel in the " \
+ "attic. I jump every time I hear a footstep on the stairs, " \
+ "certain that the theft has been discovered and that I will " \
+ "be caught. The SS officer visits less often now " \
+ "that he is sure"), 'florence')) # doctest: +ELLIPSIS
+ ('florence', -307.5473096791...)
+ """
+ def worker(message, key_length, fitness):
+ splits = every_nth(sanitised_message, key_length)
+ key = cat([unpos(-caesar_break(s)[0]) for s in splits])
+ plaintext = beaufort_variant_decipher(message, key)
+ fit = fitness(plaintext)
+ return key, fit
+ sanitised_message = sanitise(message)
results = starmap(worker, [(sanitised_message, i, fitness)
for i in range(1, max_key_length+1)])
return max(results, key=lambda k: k[1])
+def polybius_break_mp(message, column_labels, row_labels,
+ letters_to_merge=None,
+ wordlist=keywords, fitness=Pletters,
+ number_of_solutions=1, chunksize=500):
+ """Breaks a Polybius substitution cipher using a dictionary and
+ frequency analysis
+
+ >>> polybius_break_mp(polybius_encipher('this is a test message for the ' \
+ 'polybius decipherment', 'elephant', 'abcde', 'abcde'), \
+ 'abcde', 'abcde', \
+ wordlist=['cat', 'elephant', 'kangaroo']) # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
+ (('elephant', <KeywordWrapAlphabet.from_a: 1>, 'abcde', 'abcde', False), \
+ -54.53880...)
+ >>> polybius_break_mp(polybius_encipher('this is a test message for the ' \
+ 'polybius decipherment', 'elephant', 'abcde', 'abcde', column_first=True), \
+ 'abcde', 'abcde', \
+ wordlist=['cat', 'elephant', 'kangaroo']) # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
+ (('elephant', <KeywordWrapAlphabet.from_a: 1>, 'abcde', 'abcde', True), \
+ -54.53880...)
+ >>> polybius_break_mp(polybius_encipher('this is a test message for the ' \
+ 'polybius decipherment', 'elephant', 'abcde', 'abcde', column_first=False), \
+ 'abcde', 'abcde', \
+ wordlist=['cat', 'elephant', 'kangaroo']) # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
+ (('elephant', <KeywordWrapAlphabet.from_a: 1>, 'abcde', 'abcde', False), \
+ -54.53880...)
+ >>> polybius_break_mp(polybius_encipher('this is a test message for the ' \
+ 'polybius decipherment', 'elephant', 'abcde', 'pqrst', column_first=True), \
+ 'abcde', 'pqrst', \
+ wordlist=['cat', 'elephant', 'kangaroo']) # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
+ (('elephant', <KeywordWrapAlphabet.from_a: 1>, 'abcde', 'pqrst', True), \
+ -54.53880...)
+ """
+ if letters_to_merge is None:
+ letters_to_merge = {'j': 'i'}
+ with Pool() as pool:
+ helper_args = [(message, word, wrap,
+ column_labels, row_labels, column_first,
+ letters_to_merge,
+ fitness)
+ for word in wordlist
+ for wrap in KeywordWrapAlphabet
+ for column_first in [False, True]]
+ # Gotcha: the helper function here needs to be defined at the top level
+ # (limitation of Pool.starmap)
+ breaks = pool.starmap(polybius_break_worker, helper_args, chunksize)
+ 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 polybius_break_worker(message, keyword, wrap_alphabet,
+ column_order, row_order, column_first,
+ letters_to_merge,
+ fitness):
+ plaintext = polybius_decipher(message, keyword,
+ column_order, row_order,
+ column_first=column_first,
+ letters_to_merge=letters_to_merge,
+ wrap_alphabet=wrap_alphabet)
+ if plaintext:
+ fit = fitness(plaintext)
+ else:
+ fit = float('-inf')
+ logger.debug('Polybius break attempt using key {0} (wrap={1}, merging {2}), '
+ 'columns as {3}, rows as {4} (column_first={5}) '
+ 'gives fit of {6} and decrypt starting: '
+ '{7}'.format(keyword, wrap_alphabet, letters_to_merge,
+ column_order, row_order, column_first,
+ fit, sanitise(plaintext)[:50]))
+ return (keyword, wrap_alphabet, column_order, row_order, column_first), fit
+
def column_transposition_break_mp(message, translist=transpositions,
fitness=Pbigrams, chunksize=500):
fit, sanitise(plaintext)[:50]))
return matrix, fit
+def bifid_break_mp(message, wordlist=keywords, fitness=Pletters, max_period=10,
+ number_of_solutions=1, chunksize=500):
+ """Breaks a keyword substitution cipher using a dictionary and
+ frequency analysis
+
+ >>> bifid_break_mp(bifid_encipher('this is a test message for the ' \
+ 'keyword decipherment', 'elephant', wrap_alphabet=KeywordWrapAlphabet.from_last), \
+ wordlist=['cat', 'elephant', 'kangaroo']) # doctest: +ELLIPSIS
+ (('elephant', <KeywordWrapAlphabet.from_last: 2>, 0), -52.834575011...)
+ >>> bifid_break_mp(bifid_encipher('this is a test message for the ' \
+ 'keyword decipherment', 'elephant', wrap_alphabet=KeywordWrapAlphabet.from_last), \
+ wordlist=['cat', 'elephant', 'kangaroo'], \
+ number_of_solutions=2) # doctest: +ELLIPSIS, +NORMALIZE_WHITESPACE
+ [(('elephant', <KeywordWrapAlphabet.from_last: 2>, 0), -52.834575011...),
+ (('elephant', <KeywordWrapAlphabet.from_largest: 3>, 0), -52.834575011...)]
+ """
+ with Pool() as pool:
+ helper_args = [(message, word, wrap, period, fitness)
+ for word in wordlist
+ for wrap in KeywordWrapAlphabet
+ for period in range(max_period+1)]
+ # Gotcha: the helper function here needs to be defined at the top level
+ # (limitation of Pool.starmap)
+ breaks = pool.starmap(bifid_break_worker, helper_args, chunksize)
+ 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 bifid_break_worker(message, keyword, wrap_alphabet, period, fitness):
+ plaintext = bifid_decipher(message, keyword, wrap_alphabet, period=period)
+ fit = fitness(plaintext)
+ logger.debug('Keyword break attempt using key {0} (wrap={1}) gives fit of '
+ '{2} and decrypt starting: {3}'.format(keyword,
+ wrap_alphabet, fit, sanitise(plaintext)[:50]))
+ return (keyword, wrap_alphabet, period), fit
+
def pocket_enigma_break_by_crib(message, wheel_spec, crib, crib_position):
"""Break a pocket enigma using a crib (some plaintext that's expected to
projects / cipher-tools.git / blobdiff