X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=cipherbreak.py;h=d5d3aa76422c6b0109ee91d55b482d87c66c97a0;hb=b106360744be4a63f38f8a3891926a455cc96770;hp=b1af48c2e40d1ba60b948e75c758ab162f242233;hpb=14ac787d794684b5aceacb307d687597e464e7b4;p=cipher-tools.git diff --git a/cipherbreak.py b/cipherbreak.py index b1af48c..d5d3aa7 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 * @@ -199,23 +210,27 @@ def keyword_break_worker(message, keyword, wrap_alphabet, fitness): return (keyword, wrap_alphabet), fit def monoalphabetic_break_hillclimbing(message, max_iterations=10000000, - fitness=Pletters): + alphabet=None, fitness=Pletters): ciphertext = unaccent(message).lower() - alphabet = list(string.ascii_lowercase) - random.shuffle(alphabet) - alphabet = ''.join(alphabet) + 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, fitness=Pletters, chunksize=1): + max_iterations = 10000000, alphabet=None, fitness=Pletters, chunksize=1): worker_args = [] ciphertext = unaccent(message).lower() 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 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) @@ -286,7 +301,7 @@ def vigenere_frequency_break(message, max_key_length=20, fitness=Pletters): """ 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([chr(caesar_break(s)[0] + ord('a')) for s in splits]) plaintext = vigenere_decipher(message, key) fit = fitness(plaintext) return key, fit @@ -310,7 +325,7 @@ def beaufort_frequency_break(message, max_key_length=20, fitness=Pletters): """ def worker(message, key_length, fitness): splits = every_nth(sanitised_message, key_length) - key = ''.join([chr(-caesar_break(s)[0] % 26 + ord('a')) + key = cat([chr(-caesar_break(s)[0] % 26 + ord('a')) for s in splits]) plaintext = beaufort_decipher(message, key) fit = fitness(plaintext) @@ -355,7 +370,7 @@ 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 +479,64 @@ 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): @@ -526,13 +599,13 @@ 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()