X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=cipherbreak.py;h=368d669a49b2741822d983243cd5225151764d95;hb=21c390a77d42729afa23844ef2f1295106bed3de;hp=7c609ab5c16aa1e56d0529172e4733daf33b81ec;hpb=d0a53e974970bc915d94280b5158b50f93054dc3;p=cipher-tools.git diff --git a/cipherbreak.py b/cipherbreak.py index 7c609ab..368d669 100644 --- a/cipherbreak.py +++ b/cipherbreak.py @@ -13,22 +13,6 @@ from multiprocessing import Pool import matplotlib.pyplot as plt -# 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 * @@ -41,690 +25,8 @@ from language_models import * # timeit.repeat('keyword_break_mp(c5a, chunksize=500)', setup='gc.enable() ; from __main__ import c5a ; from cipher import keyword_break_mp', repeat=5, number=1) -def index_of_coincidence(text): - stext = sanitise(text) - counts = collections.Counter(stext) - denom = len(stext) * (len(text) - 1) / 26 - return ( - sum(max(counts[l] * counts[l] - 1, 0) for l in string.ascii_lowercase) - / - denom - ) - - -transpositions = collections.defaultdict(list) -for word in keywords: - transpositions[transpositions_of(word)] += [word] - -def frequencies(text): - """Count the number of occurrences of each character in text - - >>> sorted(frequencies('abcdefabc').items()) - [('a', 2), ('b', 2), ('c', 2), ('d', 1), ('e', 1), ('f', 1)] - >>> sorted(frequencies('the quick brown fox jumped over the lazy ' \ - 'dog').items()) # doctest: +NORMALIZE_WHITESPACE - [(' ', 8), ('a', 1), ('b', 1), ('c', 1), ('d', 2), ('e', 4), ('f', 1), - ('g', 1), ('h', 2), ('i', 1), ('j', 1), ('k', 1), ('l', 1), ('m', 1), - ('n', 1), ('o', 4), ('p', 1), ('q', 1), ('r', 2), ('t', 2), ('u', 2), - ('v', 1), ('w', 1), ('x', 1), ('y', 1), ('z', 1)] - >>> sorted(frequencies('The Quick BROWN fox jumped! over... the ' \ - '(9lazy) DOG').items()) # doctest: +NORMALIZE_WHITESPACE - [(' ', 8), ('!', 1), ('(', 1), (')', 1), ('.', 3), ('9', 1), ('B', 1), - ('D', 1), ('G', 1), ('N', 1), ('O', 2), ('Q', 1), ('R', 1), ('T', 1), - ('W', 1), ('a', 1), ('c', 1), ('d', 1), ('e', 4), ('f', 1), ('h', 2), - ('i', 1), ('j', 1), ('k', 1), ('l', 1), ('m', 1), ('o', 2), ('p', 1), - ('r', 1), ('t', 1), ('u', 2), ('v', 1), ('x', 1), ('y', 1), ('z', 1)] - >>> sorted(frequencies(sanitise('The Quick BROWN fox jumped! over... '\ - 'the (9lazy) DOG')).items()) # doctest: +NORMALIZE_WHITESPACE - [('a', 1), ('b', 1), ('c', 1), ('d', 2), ('e', 4), ('f', 1), ('g', 1), - ('h', 2), ('i', 1), ('j', 1), ('k', 1), ('l', 1), ('m', 1), ('n', 1), - ('o', 4), ('p', 1), ('q', 1), ('r', 2), ('t', 2), ('u', 2), ('v', 1), - ('w', 1), ('x', 1), ('y', 1), ('z', 1)] - >>> frequencies('abcdefabcdef')['x'] - 0 - """ - return collections.Counter(c for c in text) - - -def caesar_break(message, fitness=Pletters): - """Breaks a Caesar cipher using frequency analysis - - >>> caesar_break('ibxcsyorsaqcheyklxivoexlevmrimwxsfiqevvmihrsasrxliwyrh' \ - 'ecjsppsamrkwleppfmergefifvmhixscsymjcsyqeoixlm') # doctest: +ELLIPSIS - (4, -130.849989015...) - >>> caesar_break('wxwmaxdgheetgwuxztgptedbgznitgwwhpguxyhkxbmhvvtlbhgtee' \ - 'raxlmhiixweblmxgxwmhmaxybkbgztgwztsxwbgmxgmert') # doctest: +ELLIPSIS - (19, -128.82410410...) - >>> caesar_break('yltbbqnqnzvguvaxurorgenafsbezqvagbnornfgsbevpnaabjurer' \ - 'svaquvzyvxrnznazlybequrvfohgriraabjtbaruraprur') # doctest: +ELLIPSIS - (13, -126.25403935...) - """ - sanitised_message = sanitise(message) - best_shift = 0 - best_fit = float('-inf') - for shift in range(26): - plaintext = caesar_decipher(sanitised_message, shift) - fit = fitness(plaintext) - logger.debug('Caesar break attempt using key {0} gives fit of {1} ' - 'and decrypt starting: {2}'.format(shift, fit, - plaintext[:50])) - if fit > best_fit: - best_fit = fit - best_shift = shift - logger.info('Caesar break best fit: key {0} gives fit of {1} and ' - 'decrypt starting: {2}'.format(best_shift, best_fit, - caesar_decipher(sanitised_message, best_shift)[:50])) - return best_shift, best_fit - -def affine_break(message, fitness=Pletters): - """Breaks an affine cipher using frequency analysis - - >>> affine_break('lmyfu bkuusd dyfaxw claol psfaom jfasd snsfg jfaoe ls ' \ - 'omytd jlaxe mh jm bfmibj umis hfsul axubafkjamx. ls kffkxwsd jls ' \ - 'ofgbjmwfkiu olfmxmtmwaokttg jlsx ls kffkxwsd jlsi zg tsxwjl. jlsx ' \ - 'ls umfjsd jlsi zg hfsqysxog. ls dmmdtsd mx jls bats mh bkbsf. ls ' \ - 'bfmctsd kfmyxd jls lyj, mztanamyu xmc jm clm cku tmmeaxw kj lai ' \ - 'kxd clm ckuxj.') # doctest: +ELLIPSIS - ((15, 22, True), -340.601181913...) - """ - sanitised_message = sanitise(message) - best_multiplier = 0 - best_adder = 0 - best_one_based = True - best_fit = float("-inf") - for one_based in [True, False]: - for multiplier in [x for x in range(1, 26, 2) if x != 13]: - for adder in range(26): - plaintext = affine_decipher(sanitised_message, - multiplier, adder, one_based) - fit = fitness(plaintext) - logger.debug('Affine break attempt using key {0}x+{1} ({2}) ' - 'gives fit of {3} and decrypt starting: {4}'. - format(multiplier, adder, one_based, fit, - plaintext[:50])) - if fit > best_fit: - best_fit = fit - best_multiplier = multiplier - best_adder = adder - best_one_based = one_based - logger.info('Affine break best fit with key {0}x+{1} ({2}) gives fit of ' - '{3} and decrypt starting: {4}'.format( - best_multiplier, best_adder, best_one_based, best_fit, - affine_decipher(sanitised_message, best_multiplier, - best_adder, best_one_based)[:50])) - return (best_multiplier, best_adder, best_one_based), best_fit - -def keyword_break(message, wordlist=keywords, fitness=Pletters): - """Breaks a keyword substitution cipher using a dictionary and - frequency analysis. - - >>> keyword_break(keyword_encipher('this is a test message for the ' \ - 'keyword decipherment', 'elephant', KeywordWrapAlphabet.from_last), \ - wordlist=['cat', 'elephant', 'kangaroo']) # doctest: +ELLIPSIS - (('elephant', ), -52.834575011...) - """ - best_keyword = '' - best_wrap_alphabet = True - best_fit = float("-inf") - for wrap_alphabet in KeywordWrapAlphabet: - for keyword in wordlist: - 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])) - if fit > best_fit: - best_fit = fit - best_keyword = keyword - best_wrap_alphabet = wrap_alphabet - logger.info('Keyword break best fit with key {0} (wrap={1}) gives fit of ' - '{2} and decrypt starting: {3}'.format(best_keyword, - best_wrap_alphabet, best_fit, sanitise( - keyword_decipher(message, best_keyword, - best_wrap_alphabet))[:50])) - return (best_keyword, best_wrap_alphabet), best_fit - -def keyword_break_mp(message, wordlist=keywords, fitness=Pletters, - number_of_solutions=1, chunksize=500): - """Breaks a keyword substitution cipher using a dictionary and - frequency analysis - - >>> 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', ), -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', ), -52.834575011...), - (('elephant', ), -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(best_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[:50]) -# return best_alphabet, best_fitness - - -def monoalphabetic_break_hillclimbing(message, - max_iterations=20000, - plain_alphabet=None, - cipher_alphabet=None, - fitness=Pletters, chunksize=1): - return simulated_annealing_break(message, - workers=1, - initial_temperature=0, - max_iterations=max_iterations, - plain_alphabet=plain_alphabet, - cipher_alphabet=cipher_alphabet, - fitness=fitness, chunksize=chunksize) - - -def monoalphabetic_break_hillclimbing_mp(message, - workers=10, - max_iterations=20000, - plain_alphabet=None, - cipher_alphabet=None, - fitness=Pletters, chunksize=1): - return simulated_annealing_break(message, - workers=workers, - initial_temperature=0, - max_iterations=max_iterations, - plain_alphabet=plain_alphabet, - cipher_alphabet=cipher_alphabet, - fitness=fitness, chunksize=chunksize) - - -def simulated_annealing_break(message, workers=10, - initial_temperature=200, - max_iterations=20000, - plain_alphabet=None, - cipher_alphabet=None, - fitness=Pletters, chunksize=1): - worker_args = [] - ciphertext = sanitise(message) - for i in range(workers): - if not plain_alphabet: - plain_alphabet = string.ascii_lowercase - if not cipher_alphabet: - cipher_alphabet = list(string.ascii_lowercase) - random.shuffle(cipher_alphabet) - cipher_alphabet = cat(cipher_alphabet) - worker_args.append((ciphertext, plain_alphabet, cipher_alphabet, - initial_temperature, max_iterations, fitness)) - with Pool() as pool: - breaks = pool.starmap(simulated_annealing_break_worker, - worker_args, chunksize) - return max(breaks, key=lambda k: k[1]) - - -def simulated_annealing_break_worker(message, plain_alphabet, cipher_alphabet, - t0, 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:]) - - temperature = t0 - - dt = t0 / (0.9 * max_iterations) - - current_alphabet = cipher_alphabet - alphabet = current_alphabet - cipher_translation = ''.maketrans(current_alphabet, plain_alphabet) - plaintext = message.translate(cipher_translation) - current_fitness = fitness(plaintext) - - best_alphabet = current_alphabet - best_fitness = current_fitness - best_plaintext = plaintext - - # print('starting for', max_iterations) - for i in range(max_iterations): - swap_a = random.randrange(26) - swap_b = (swap_a + int(random.gauss(0, 4))) % 26 - alphabet = swap(current_alphabet, swap_a, swap_b) - cipher_translation = ''.maketrans(alphabet, plain_alphabet) - plaintext = message.translate(cipher_translation) - new_fitness = fitness(plaintext) - try: - sa_chance = math.exp((new_fitness - current_fitness) / temperature) - except (OverflowError, ZeroDivisionError): - # print('exception triggered: new_fit {}, current_fit {}, temp {}'.format(new_fitness, current_fitness, temperature)) - sa_chance = 0 - if (new_fitness > current_fitness or random.random() < sa_chance): - # logger.debug('Simulated annealing: iteration {}, temperature {}, ' - # 'current alphabet {}, current_fitness {}, ' - # 'best_plaintext {}'.format(i, temperature, current_alphabet, - # current_fitness, best_plaintext[:50])) - - # logger.debug('new_fit {}, current_fit {}, temp {}, sa_chance {}'.format(new_fitness, current_fitness, temperature, sa_chance)) - current_fitness = new_fitness - current_alphabet = alphabet - - if current_fitness > best_fitness: - best_alphabet = current_alphabet - best_fitness = current_fitness - best_plaintext = plaintext - if i % 500 == 0: - logger.debug('Simulated annealing: iteration {}, temperature {}, ' - 'current alphabet {}, current_fitness {}, ' - 'best_plaintext {}'.format(i, temperature, current_alphabet, - current_fitness, plaintext[:50])) - temperature = max(temperature - dt, 0.001) - - return best_alphabet, best_fitness # current_alphabet, current_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', , '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', , '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', , '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', , '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 railfence 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]) def amsco_break(message, translist=transpositions, patterns = [(1, 2), (2, 1)], fillstyles = [AmscoFillStyle.continuous,