- >>> keyword_break_mp(keyword_encipher('this is a test message for the ' \
- '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)
- for word in wordlist
- for wrap in KeywordWrapAlphabet]
- # 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)
- 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)
- 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), fit
-
-def monoalphabetic_break_hillclimbing(message, max_iterations=10000000,
- alphabet=None, fitness=Pletters):
- ciphertext = unaccent(message).lower()
- if not alphabet:
- alphabet = list(string.ascii_lowercase)
- random.shuffle(alphabet)
- alphabet = cat(alphabet)
- return monoalphabetic_break_hillclimbing_worker(ciphertext, alphabet,
- max_iterations, fitness)
-
-def monoalphabetic_break_hillclimbing_mp(message, workers=10,
- max_iterations = 10000000, alphabet=None, fitness=Pletters, chunksize=1):
- worker_args = []
- ciphertext = unaccent(message).lower()
- for i in range(workers):
- if alphabet:
- this_alphabet = alphabet
- else:
- this_alphabet = list(string.ascii_lowercase)
- random.shuffle(this_alphabet)
- this_alphabet = cat(this_alphabet)
- worker_args.append((ciphertext, this_alphabet, max_iterations, fitness))
- with Pool() as pool:
- breaks = pool.starmap(monoalphabetic_break_hillclimbing_worker,
- worker_args, chunksize)
- return max(breaks, key=lambda k: k[1])
-
-def monoalphabetic_break_hillclimbing_worker(message, alphabet,
- max_iterations, fitness):
- def swap(letters, i, j):
- if i > j:
- i, j = j, i
- if i == j:
- return letters
- else:
- return (letters[:i] + letters[j] + letters[i+1:j] + letters[i] +
- letters[j+1:])
- best_alphabet = alphabet
- best_fitness = float('-inf')
- for i in range(max_iterations):
- alphabet = swap(alphabet, random.randrange(26), random.randrange(26))
- cipher_translation = ''.maketrans(string.ascii_lowercase, alphabet)
- plaintext = message.translate(cipher_translation)
- if fitness(plaintext) > best_fitness:
- best_fitness = fitness(plaintext)
- best_alphabet = alphabet
- print(i, best_alphabet, best_fitness, plaintext)
- return best_alphabet, best_fitness
-
-
-def vigenere_keyword_break_mp(message, wordlist=keywords, fitness=Pletters,
- chunksize=500):
- """Breaks a vigenere cipher using a dictionary and frequency analysis.
-
- >>> vigenere_keyword_break_mp(vigenere_encipher(sanitise('this is a test ' \
- 'message for the vigenere decipherment'), 'cat'), \
- wordlist=['cat', 'elephant', 'kangaroo']) # doctest: +ELLIPSIS
- ('cat', -52.9472712...)
- """
- with Pool() as pool:
- helper_args = [(message, word, fitness)
- for word in wordlist]
- # Gotcha: the helper function here needs to be defined at the top level
- # (limitation of Pool.starmap)
- breaks = pool.starmap(vigenere_keyword_break_worker, helper_args,
- chunksize)
- return max(breaks, key=lambda k: k[1])
-vigenere_keyword_break = vigenere_keyword_break_mp
-
-def vigenere_keyword_break_worker(message, keyword, fitness):
- plaintext = vigenere_decipher(message, keyword)
- fit = fitness(plaintext)
- logger.debug('Vigenere keyword break attempt using key {0} gives fit of '
- '{1} and decrypt starting: {2}'.format(keyword,
- fit, sanitise(plaintext)[:50]))
- return keyword, fit
-
-
-def vigenere_frequency_break(message, max_key_length=20, fitness=Pletters):
- """Breaks a Vigenere cipher with frequency analysis
-
- >>> vigenere_frequency_break(vigenere_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', -307.5473096...)
- """
- 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 = vigenere_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_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
-
- >>> beaufort_frequency_break(beaufort_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(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):
- """Breaks a column transposition cipher using a dictionary and
- n-gram frequency analysis
-
- >>> column_transposition_break_mp(column_transposition_encipher(sanitise( \
- "It is a truth universally acknowledged, that a single man in \
- possession of a good fortune, must be in want of a wife. However \
- little known the feelings or views of such a man may be on his \
- first entering a neighbourhood, this truth is so well fixed in \
- the minds of the surrounding families, that he is considered the \
- rightful property of some one or other of their daughters."), \
- 'encipher'), \
- translist={(2, 0, 5, 3, 1, 4, 6): ['encipher'], \
- (5, 0, 6, 1, 3, 4, 2): ['fourteen'], \
- (6, 1, 0, 4, 5, 3, 2): ['keyword']}) # doctest: +ELLIPSIS
- (((2, 0, 5, 3, 1, 4, 6), False, False), -709.4646722...)
- >>> column_transposition_break_mp(column_transposition_encipher(sanitise( \
- "It is a truth universally acknowledged, that a single man in \
- possession of a good fortune, must be in want of a wife. However \
- little known the feelings or views of such a man may be on his \
- first entering a neighbourhood, this truth is so well fixed in \
- the minds of the surrounding families, that he is considered the \
- rightful property of some one or other of their daughters."), \
- 'encipher'), \
- translist={(2, 0, 5, 3, 1, 4, 6): ['encipher'], \
- (5, 0, 6, 1, 3, 4, 2): ['fourteen'], \
- (6, 1, 0, 4, 5, 3, 2): ['keyword']}, \
- fitness=Ptrigrams) # doctest: +ELLIPSIS
- (((2, 0, 5, 3, 1, 4, 6), False, False), -997.0129085...)
- """
- with Pool() as pool:
- helper_args = [(message, trans, fillcolumnwise, emptycolumnwise,
- fitness)
- for trans in translist
- for fillcolumnwise in [True, False]
- for emptycolumnwise in [True, False]]
- # Gotcha: the helper function here needs to be defined at the top level
- # (limitation of Pool.starmap)
- breaks = pool.starmap(column_transposition_break_worker,
- helper_args, chunksize)
- return max(breaks, key=lambda k: k[1])
-column_transposition_break = column_transposition_break_mp
-
-def column_transposition_break_worker(message, transposition,
- fillcolumnwise, emptycolumnwise, fitness):
- plaintext = column_transposition_decipher(message, transposition,
- fillcolumnwise=fillcolumnwise, emptycolumnwise=emptycolumnwise)
- fit = fitness(sanitise(plaintext))
- logger.debug('Column transposition break attempt using key {0} '
- 'gives fit of {1} and decrypt starting: {2}'.format(
- transposition, fit,
- sanitise(plaintext)[:50]))
- return (transposition, fillcolumnwise, emptycolumnwise), fit
-
-
-def scytale_break_mp(message, max_key_length=20,
- fitness=Pbigrams, chunksize=500):
- """Breaks a scytale cipher using a range of lengths and
- n-gram frequency analysis
-
- >>> scytale_break_mp(scytale_encipher(sanitise( \
- "It is a truth universally acknowledged, that a single man in \
- possession of a good fortune, must be in want of a wife. However \
- little known the feelings or views of such a man may be on his \
- first entering a neighbourhood, this truth is so well fixed in \
- the minds of the surrounding families, that he is considered the \
- rightful property of some one or other of their daughters."), \
- 5)) # doctest: +ELLIPSIS
- (5, -709.4646722...)
- >>> scytale_break_mp(scytale_encipher(sanitise( \
- "It is a truth universally acknowledged, that a single man in \
- possession of a good fortune, must be in want of a wife. However \
- little known the feelings or views of such a man may be on his \
- first entering a neighbourhood, this truth is so well fixed in \
- the minds of the surrounding families, that he is considered the \
- rightful property of some one or other of their daughters."), \
- 5), \
- fitness=Ptrigrams) # doctest: +ELLIPSIS
- (5, -997.0129085...)
- """
- with Pool() as pool:
- helper_args = [(message, trans, False, True, fitness)
- for trans in
- [[col for col in range(math.ceil(len(message)/rows))]
- for rows in range(1,max_key_length+1)]]
- # Gotcha: the helper function here needs to be defined at the top level
- # (limitation of Pool.starmap)
- breaks = pool.starmap(column_transposition_break_worker,
- helper_args, chunksize)
- best = max(breaks, key=lambda k: k[1])
- return math.trunc(len(message) / len(best[0][0])), best[1]
-scytale_break = scytale_break_mp
-
-
-def railfence_break(message, max_key_length=20,
- fitness=Pletters, chunksize=500):
- """Breaks a hill cipher using a matrix of given rank and letter frequencies
-
-
- """
-
- sanitised_message = sanitise(message)
- results = starmap(worker, [(sanitised_message, i, fitness)
- for i in range(2, max_key_length+1)])
- return max(results, key=lambda k: k[1])
-
-
-def railfence_break(message, max_key_length=20,
- fitness=Pbigrams, chunksize=500):
- """Breaks a railfence cipher using a range of lengths and
- n-gram frequency analysis
-
- >>> railfence_break(railfence_encipher(sanitise( \
- "It is a truth universally acknowledged, that a single man in \
- possession of a good fortune, must be in want of a wife. However \
- little known the feelings or views of such a man may be on his \
- first entering a neighbourhood, this truth is so well fixed in \
- the minds of the surrounding families, that he is considered the \
- rightful property of some one or other of their daughters."), \
- 7)) # doctest: +ELLIPSIS
- (7, -709.46467226...)
- >>> railfence_break(railfence_encipher(sanitise( \
- "It is a truth universally acknowledged, that a single man in \
- possession of a good fortune, must be in want of a wife. However \
- little known the feelings or views of such a man may be on his \
- first entering a neighbourhood, this truth is so well fixed in \
- the minds of the surrounding families, that he is considered the \
- rightful property of some one or other of their daughters."), \
- 7), \
- fitness=Ptrigrams) # doctest: +ELLIPSIS
- (7, -997.0129085...)
- """
- def worker(message, height, fitness):
- plaintext = railfence_decipher(message, height)
- fit = fitness(plaintext)
- return height, fit
-
- sanitised_message = sanitise(message)
- results = starmap(worker, [(sanitised_message, i, fitness)
- for i in range(2, max_key_length+1)])
- return max(results, key=lambda k: k[1])