X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=cipherbreak.py;h=de605d34d67b49e214cab7d280b1eb19cc76b8bf;hb=5334c6e49cc35db0df35322a77ba0efe94a4abdd;hp=b1af48c2e40d1ba60b948e75c758ab162f242233;hpb=14ac787d794684b5aceacb307d687597e464e7b4;p=cipher-tools.git diff --git a/cipherbreak.py b/cipherbreak.py index b1af48c..de605d3 100644 --- a/cipherbreak.py +++ b/cipherbreak.py @@ -13,11 +13,22 @@ from multiprocessing import Pool import matplotlib.pyplot as plt -logger = logging.getLogger(__name__) -logger.addHandler(logging.FileHandler('cipher.log')) +# 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) +# 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 * @@ -29,6 +40,18 @@ from language_models import * # timeit.timeit('keyword_break(c5a)', setup='gc.enable() ; from __main__ import c5a ; from cipher import keyword_break', number=1) # 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] @@ -198,31 +221,110 @@ def keyword_break_worker(message, keyword, wrap_alphabet, fitness): wrap_alphabet, fit, sanitise(plaintext)[:50])) return (keyword, wrap_alphabet), fit -def monoalphabetic_break_hillclimbing(message, max_iterations=10000000, - fitness=Pletters): - ciphertext = unaccent(message).lower() - alphabet = list(string.ascii_lowercase) - random.shuffle(alphabet) - alphabet = ''.join(alphabet) - return monoalphabetic_break_hillclimbing_worker(ciphertext, alphabet, - max_iterations, fitness) - -def monoalphabetic_break_hillclimbing_mp(message, workers=10, - max_iterations = 10000000, fitness=Pletters, chunksize=1): +# 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 = unaccent(message).lower() + ciphertext = sanitise(message) for i in range(workers): - alphabet = list(string.ascii_lowercase) - random.shuffle(alphabet) - alphabet = ''.join(alphabet) - worker_args.append((ciphertext, alphabet, max_iterations, fitness)) + 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(monoalphabetic_break_hillclimbing_worker, + breaks = pool.starmap(simulated_annealing_break_worker, worker_args, chunksize) return max(breaks, key=lambda k: k[1]) -def monoalphabetic_break_hillclimbing_worker(message, alphabet, - max_iterations, fitness): + +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 @@ -231,17 +333,56 @@ def monoalphabetic_break_hillclimbing_worker(message, alphabet, else: return (letters[:i] + letters[j] + letters[i+1:j] + letters[i] + letters[j+1:]) - best_alphabet = alphabet - best_fitness = float('-inf') + + 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): - alphabet = swap(alphabet, random.randrange(26), random.randrange(26)) - cipher_translation = ''.maketrans(string.ascii_lowercase, alphabet) + 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) - if fitness(plaintext) > best_fitness: - best_fitness = fitness(plaintext) - best_alphabet = alphabet - print(i, best_alphabet, best_fitness, plaintext) - return best_alphabet, best_fitness + 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, @@ -251,7 +392,7 @@ def vigenere_keyword_break_mp(message, wordlist=keywords, fitness=Pletters, >>> 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) @@ -282,11 +423,11 @@ def vigenere_frequency_break(message, max_key_length=20, fitness=Pletters): "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 = ''.join([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 @@ -296,6 +437,33 @@ def vigenere_frequency_break(message, max_key_length=20, fitness=Pletters): 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 @@ -309,17 +477,111 @@ def beaufort_frequency_break(message, max_key_length=20, fitness=Pletters): ('florence', -307.5473096791...) """ def worker(message, key_length, fitness): - splits = every_nth(sanitised_message, key_length) - key = ''.join([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', , '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): @@ -355,7 +617,7 @@ def column_transposition_break_mp(message, translist=transpositions, with Pool() as pool: helper_args = [(message, trans, fillcolumnwise, emptycolumnwise, fitness) - for trans in translist.keys() + 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 @@ -464,6 +726,64 @@ def railfence_break(message, max_key_length=20, 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, + AmscoFillStyle.same_each_row, + AmscoFillStyle.reverse_each_row], + fitness=Pbigrams, + chunksize=500): + """Breaks an AMSCO transposition cipher using a dictionary and + n-gram frequency analysis + + >>> amsco_break(amsco_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']}, \ + patterns=[(1, 2)]) # doctest: +ELLIPSIS + (((2, 0, 5, 3, 1, 4, 6), (1, 2), ), -709.4646722...) + >>> amsco_break(amsco_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', fillpattern=(2, 1)), \ + 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']}, \ + patterns=[(1, 2), (2, 1)], fitness=Ptrigrams) # doctest: +ELLIPSIS + (((2, 0, 5, 3, 1, 4, 6), (2, 1), ), -997.0129085...) + """ + with Pool() as pool: + helper_args = [(message, trans, pattern, fillstyle, fitness) + for trans in translist + for pattern in patterns + for fillstyle in fillstyles] + # Gotcha: the helper function here needs to be defined at the top level + # (limitation of Pool.starmap) + breaks = pool.starmap(amsco_break_worker, helper_args, chunksize) + return max(breaks, key=lambda k: k[1]) + +def amsco_break_worker(message, transposition, + pattern, fillstyle, fitness): + plaintext = amsco_transposition_decipher(message, transposition, + fillpattern=pattern, fillstyle=fillstyle) + fit = fitness(sanitise(plaintext)) + logger.debug('AMSCO transposition break attempt using key {0} and pattern' + '{1} ({2}) gives fit of {3} and decrypt starting: ' + '{4}'.format( + transposition, pattern, fillstyle, fit, + sanitise(plaintext)[:50])) + return (transposition, pattern, fillstyle), fit + def hill_break(message, matrix_size=2, fitness=Pletters, number_of_solutions=1, chunksize=500): @@ -496,6 +816,43 @@ def hill_break_worker(message, matrix, fitness): 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', , 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', , 0), -52.834575011...), + (('elephant', , 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 @@ -526,13 +883,13 @@ def pocket_enigma_break_by_crib(message, wheel_spec, crib, crib_position): def plot_frequency_histogram(freqs, sort_key=None): - x = range(len(freqs.keys())) - y = [freqs[l] for l in sorted(freqs.keys(), key=sort_key)] + x = range(len(freqs)) + y = [freqs[l] for l in sorted(freqs, key=sort_key)] f = plt.figure() ax = f.add_axes([0.1, 0.1, 0.9, 0.9]) ax.bar(x, y, align='center') ax.set_xticks(x) - ax.set_xticklabels(sorted(freqs.keys(), key=sort_key)) + ax.set_xticklabels(sorted(freqs, key=sort_key)) f.show()