from numpy import matrix
from numpy import linalg
from language_models import *
+import pprint
+
+
+## Utility functions
+cat = ''.join
+wcat = ' '.join
+
+def pos(letter):
+ if letter in string.ascii_lowercase:
+ return ord(letter) - ord('a')
+ elif letter in string.ascii_uppercase:
+ return ord(letter) - ord('A')
+ else:
+ return ''
+
+def unpos(number): return chr(number % 26 + ord('a'))
modular_division_table = [[0]*26 for _ in range(26)]
['afkpuz', 'bglqv!', 'chmrw!', 'dinsx!', 'ejoty!']
"""
split_text = chunks(text, n, fillvalue)
- return [''.join(l) for l in zip_longest(*split_text, fillvalue=fillvalue)]
+ return [cat(l) for l in zip_longest(*split_text, fillvalue=fillvalue)]
def combine_every_nth(split_text):
"""Reforms a text split into every_nth strings
>>> combine_every_nth(every_nth(string.ascii_lowercase, 26))
'abcdefghijklmnopqrstuvwxyz'
"""
- return ''.join([''.join(l)
+ return cat([cat(l)
for l in zip_longest(*split_text, fillvalue='')])
def chunks(text, n, fillvalue=None):
>>> caesar_encipher_letter('é', 1)
'f'
"""
+ # letter = unaccent(accented_letter)
+ # if letter in string.ascii_letters:
+ # if letter in string.ascii_uppercase:
+ # alphabet_start = ord('A')
+ # else:
+ # alphabet_start = ord('a')
+ # return chr(((ord(letter) - alphabet_start + shift) % 26) +
+ # alphabet_start)
+ # else:
+ # return letter
+
letter = unaccent(accented_letter)
if letter in string.ascii_letters:
+ cipherletter = unpos(pos(letter) + shift)
if letter in string.ascii_uppercase:
- alphabet_start = ord('A')
+ return cipherletter.upper()
else:
- alphabet_start = ord('a')
- return chr(((ord(letter) - alphabet_start + shift) % 26) +
- alphabet_start)
+ return cipherletter
else:
return letter
'Jgnnq Yqtnf!'
"""
enciphered = [caesar_encipher_letter(l, shift) for l in message]
- return ''.join(enciphered)
+ return cat(enciphered)
def caesar_decipher(message, shift):
"""Decipher a message with the Caesar cipher of given shift
def affine_encipher_letter(accented_letter, multiplier=1, adder=0, one_based=True):
"""Encipher a letter, given a multiplier and adder
- >>> ''.join([affine_encipher_letter(l, 3, 5, True) \
- for l in string.ascii_uppercase])
- 'HKNQTWZCFILORUXADGJMPSVYBE'
- >>> ''.join([affine_encipher_letter(l, 3, 5, False) \
- for l in string.ascii_uppercase])
- 'FILORUXADGJMPSVYBEHKNQTWZC'
+ >>> cat(affine_encipher_letter(l, 3, 5, True) \
+ for l in string.ascii_letters)
+ 'hknqtwzcfiloruxadgjmpsvybeHKNQTWZCFILORUXADGJMPSVYBE'
+ >>> cat(affine_encipher_letter(l, 3, 5, False) \
+ for l in string.ascii_letters)
+ 'filoruxadgjmpsvybehknqtwzcFILORUXADGJMPSVYBEHKNQTWZC'
"""
+ # letter = unaccent(accented_letter)
+ # if letter in string.ascii_letters:
+ # if letter in string.ascii_uppercase:
+ # alphabet_start = ord('A')
+ # else:
+ # alphabet_start = ord('a')
+ # letter_number = ord(letter) - alphabet_start
+ # if one_based: letter_number += 1
+ # cipher_number = (letter_number * multiplier + adder) % 26
+ # if one_based: cipher_number -= 1
+ # return chr(cipher_number % 26 + alphabet_start)
+ # else:
+ # return letter
letter = unaccent(accented_letter)
if letter in string.ascii_letters:
- if letter in string.ascii_uppercase:
- alphabet_start = ord('A')
- else:
- alphabet_start = ord('a')
- letter_number = ord(letter) - alphabet_start
+ letter_number = pos(letter)
if one_based: letter_number += 1
cipher_number = (letter_number * multiplier + adder) % 26
if one_based: cipher_number -= 1
- return chr(cipher_number % 26 + alphabet_start)
+ if letter in string.ascii_uppercase:
+ return unpos(cipher_number).upper()
+ else:
+ return unpos(cipher_number)
else:
return letter
def affine_decipher_letter(letter, multiplier=1, adder=0, one_based=True):
"""Encipher a letter, given a multiplier and adder
- >>> ''.join([affine_decipher_letter(l, 3, 5, True) \
- for l in 'HKNQTWZCFILORUXADGJMPSVYBE'])
- 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
- >>> ''.join([affine_decipher_letter(l, 3, 5, False) \
- for l in 'FILORUXADGJMPSVYBEHKNQTWZC'])
- 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
+ >>> cat(affine_decipher_letter(l, 3, 5, True) \
+ for l in 'hknqtwzcfiloruxadgjmpsvybeHKNQTWZCFILORUXADGJMPSVYBE')
+ 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
+ >>> cat(affine_decipher_letter(l, 3, 5, False) \
+ for l in 'filoruxadgjmpsvybehknqtwzcFILORUXADGJMPSVYBEHKNQTWZC')
+ 'abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ'
"""
+ # if letter in string.ascii_letters:
+ # if letter in string.ascii_uppercase:
+ # alphabet_start = ord('A')
+ # else:
+ # alphabet_start = ord('a')
+ # cipher_number = ord(letter) - alphabet_start
+ # if one_based: cipher_number += 1
+ # plaintext_number = (
+ # modular_division_table[multiplier]
+ # [(cipher_number - adder) % 26])
+ # if one_based: plaintext_number -= 1
+ # return chr(plaintext_number % 26 + alphabet_start)
+ # else:
+ # return letter
if letter in string.ascii_letters:
- if letter in string.ascii_uppercase:
- alphabet_start = ord('A')
- else:
- alphabet_start = ord('a')
- cipher_number = ord(letter) - alphabet_start
+ cipher_number = pos(letter)
if one_based: cipher_number += 1
plaintext_number = (
modular_division_table[multiplier]
[(cipher_number - adder) % 26])
if one_based: plaintext_number -= 1
- return chr(plaintext_number % 26 + alphabet_start)
+ if letter in string.ascii_uppercase:
+ return unpos(plaintext_number).upper()
+ else:
+ return unpos(plaintext_number)
else:
return letter
"""
enciphered = [affine_encipher_letter(l, multiplier, adder, one_based)
for l in message]
- return ''.join(enciphered)
+ return cat(enciphered)
def affine_decipher(message, multiplier=1, adder=0, one_based=True):
"""Decipher a message
"""
enciphered = [affine_decipher_letter(l, multiplier, adder, one_based)
for l in message]
- return ''.join(enciphered)
+ return cat(enciphered)
class KeywordWrapAlphabet(Enum):
'bayeszcdfghijklmnopqrtuvwx'
"""
if wrap_alphabet == KeywordWrapAlphabet.from_a:
- cipher_alphabet = ''.join(deduplicate(sanitise(keyword) +
+ cipher_alphabet = cat(deduplicate(sanitise(keyword) +
string.ascii_lowercase))
else:
if wrap_alphabet == KeywordWrapAlphabet.from_last:
last_keyword_letter = sorted(sanitise(keyword))[-1]
last_keyword_position = string.ascii_lowercase.find(
last_keyword_letter) + 1
- cipher_alphabet = ''.join(
+ cipher_alphabet = cat(
deduplicate(sanitise(keyword) +
string.ascii_lowercase[last_keyword_position:] +
string.ascii_lowercase))
"""
shifts = [ord(l) - ord('a') for l in sanitise(keyword)]
pairs = zip(message, cycle(shifts))
- return ''.join([caesar_encipher_letter(l, k) for l, k in pairs])
+ return cat([caesar_encipher_letter(l, k) for l, k in pairs])
def vigenere_decipher(message, keyword):
"""Vigenere decipher
"""
shifts = [ord(l) - ord('a') for l in sanitise(keyword)]
pairs = zip(message, cycle(shifts))
- return ''.join([caesar_decipher_letter(l, k) for l, k in pairs])
+ return cat([caesar_decipher_letter(l, k) for l, k in pairs])
beaufort_encipher=vigenere_decipher
beaufort_decipher=vigenere_encipher
if emptycolumnwise:
return combine_every_nth(transposed)
else:
- return ''.join(chain(*transposed))
+ return cat(chain(*transposed))
def column_transposition_decipher(message, keyword, fillvalue=' ',
fillcolumnwise=False,
if fillcolumnwise:
return combine_every_nth(untransposed)
else:
- return ''.join(chain(*untransposed))
+ return cat(chain(*untransposed))
def scytale_encipher(message, rows, fillvalue=' '):
"""Enciphers using the scytale transposition cipher.
sections = chunks(message, (height - 1) * 2, fillvalue=fillvalue)
n_sections = len(sections)
# Add the top row
- rows = [''.join([s[0] for s in sections])]
+ rows = [cat([s[0] for s in sections])]
# process the middle rows of the grid
for r in range(1, height-1):
- rows += [''.join([s[r:r+1] + s[height*2-r-2:height*2-r-1] for s in sections])]
+ rows += [cat([s[r:r+1] + s[height*2-r-2:height*2-r-1] for s in sections])]
# process the bottom row
- rows += [''.join([s[height - 1:height] for s in sections])]
- # rows += [' '.join([s[height - 1] for s in sections])]
- return ''.join(rows)
+ rows += [cat([s[height - 1:height] for s in sections])]
+ # rows += [wcat([s[height - 1] for s in sections])]
+ return cat(rows)
def railfence_decipher(message, height, fillvalue=''):
"""Railfence decipher.
down_rows = [rows[0]]
up_rows = []
for i in range(1, height-1):
- down_rows += [''.join([c for n, c in enumerate(rows[i]) if n % 2 == 0])]
- up_rows += [''.join([c for n, c in enumerate(rows[i]) if n % 2 == 1])]
+ down_rows += [cat([c for n, c in enumerate(rows[i]) if n % 2 == 0])]
+ up_rows += [cat([c for n, c in enumerate(rows[i]) if n % 2 == 1])]
down_rows += [rows[-1]]
up_rows.reverse()
- return ''.join(c for r in zip_longest(*(down_rows + up_rows), fillvalue='') for c in r)
+ return cat(c for r in zip_longest(*(down_rows + up_rows), fillvalue='') for c in r)
def make_cadenus_keycolumn(doubled_letters = 'vw', start='a', reverse=False):
"""Makes the key column for a Cadenus cipher (the column down between the
index_to_remove = string.ascii_lowercase.find(doubled_letters[0])
short_alphabet = string.ascii_lowercase[:index_to_remove] + string.ascii_lowercase[index_to_remove+1:]
if reverse:
- short_alphabet = ''.join(reversed(short_alphabet))
+ short_alphabet = cat(reversed(short_alphabet))
start_pos = short_alphabet.find(start)
rotated_alphabet = short_alphabet[start_pos:] + short_alphabet[:start_pos]
keycolumn = {l: i for i, l in enumerate(rotated_alphabet)}
rotated_rows = zip(*rotated_columns)
transpositions = transpositions_of(keyword)
transposed = [transpose(r, transpositions) for r in rotated_rows]
- return ''.join(chain(*transposed))
+ return cat(chain(*transposed))
def cadenus_decipher(message, keyword, keycolumn, fillvalue='a'):
"""
rotated_columns = [col[-start:] + col[:-start] for start, col in zip([keycolumn[l] for l in keyword], columns)]
rotated_rows = zip(*rotated_columns)
# return rotated_columns
- return ''.join(chain(*rotated_rows))
+ return cat(chain(*rotated_rows))
def hill_encipher(matrix, message_letters, fillvalue='a'):
# message_chunks = chunks(message, len(matrix), fillvalue=None)
enciphered_chunks = [((matrix * np.matrix(c).T).T).tolist()[0]
for c in message_chunks]
- return ''.join([chr(int(round(l)) % 26 + ord('a'))
+ return cat([chr(int(round(l)) % 26 + ord('a'))
for l in sum(enciphered_chunks, [])])
def hill_decipher(matrix, message, fillvalue='a'):
for slice in transposed_sections:
plaintext_list[slice.index] = message[current_pos:current_pos-slice.start+slice.end][:len(message[slice.start:slice.end])]
current_pos += len(message[slice.start:slice.end])
- return ''.join(plaintext_list)
+ return cat(plaintext_list)
+
+
+def bifid_grid(keyword, wrap_alphabet, letter_mapping):
+ """Create the grids for a Bifid cipher
+ """
+ cipher_alphabet = keyword_cipher_alphabet_of(keyword, wrap_alphabet)
+ if letter_mapping is None:
+ letter_mapping = {'j': 'i'}
+ translation = ''.maketrans(letter_mapping)
+ cipher_alphabet = cat(collections.OrderedDict.fromkeys(cipher_alphabet.translate(translation)))
+ f_grid = {k: ((i // 5) + 1, (i % 5) + 1)
+ for i, k in enumerate(cipher_alphabet)}
+ r_grid = {((i // 5) + 1, (i % 5) + 1): k
+ for i, k in enumerate(cipher_alphabet)}
+ return translation, f_grid, r_grid
+
+def bifid_encipher(message, keyword, wrap_alphabet=KeywordWrapAlphabet.from_a,
+ letter_mapping=None, period=None, fillvalue=None):
+ """Bifid cipher
+
+ >>> bifid_encipher("indiajelly", 'iguana')
+ 'ibidonhprm'
+ >>> bifid_encipher("indiacurry", 'iguana', period=4)
+ 'ibnhgaqltm'
+ >>> bifid_encipher("indiacurry", 'iguana', period=4, fillvalue='x')
+ 'ibnhgaqltzml'
+ """
+ translation, f_grid, r_grid = bifid_grid(keyword, wrap_alphabet, letter_mapping)
+
+ t_message = message.translate(translation)
+ pairs0 = [f_grid[l] for l in sanitise(t_message)]
+ if period:
+ chunked_pairs = [pairs0[i:i+period] for i in range(0, len(pairs0), period)]
+ if len(chunked_pairs[-1]) < period and fillvalue:
+ chunked_pairs[-1] += [f_grid[fillvalue]] * (period - len(chunked_pairs[-1]))
+ else:
+ chunked_pairs = [pairs0]
+
+ pairs1 = []
+ for c in chunked_pairs:
+ items = sum(list(list(i) for i in zip(*c)), [])
+ p = [(items[i], items[i+1]) for i in range(0, len(items), 2)]
+ pairs1 += p
+
+ return cat(r_grid[p] for p in pairs1)
+
+
+def bifid_decipher(message, keyword, wrap_alphabet=KeywordWrapAlphabet.from_a,
+ letter_mapping=None, period=None, fillvalue=None):
+ """Decipher with bifid cipher
+
+ >>> bifid_decipher('ibidonhprm', 'iguana')
+ 'indiaielly'
+ >>> bifid_decipher("ibnhgaqltm", 'iguana', period=4)
+ 'indiacurry'
+ >>> bifid_decipher("ibnhgaqltzml", 'iguana', period=4)
+ 'indiacurryxx'
+ """
+ translation, f_grid, r_grid = bifid_grid(keyword, wrap_alphabet, letter_mapping)
+
+ t_message = message.translate(translation)
+ pairs0 = [f_grid[l] for l in sanitise(t_message)]
+ if period:
+ chunked_pairs = [pairs0[i:i+period] for i in range(0, len(pairs0), period)]
+ if len(chunked_pairs[-1]) < period and fillvalue:
+ chunked_pairs[-1] += [f_grid[fillvalue]] * (period - len(chunked_pairs[-1]))
+ else:
+ chunked_pairs = [pairs0]
+
+ pairs1 = []
+ for c in chunked_pairs:
+ items = [j for i in c for j in i]
+ gap = len(c)
+ p = [(items[i], items[i+gap]) for i in range(gap)]
+ pairs1 += p
+ return cat(r_grid[p] for p in pairs1)
class PocketEnigma(object):
"""A pocket enigma machine
>>> pe.set_position('f')
5
- >>> ''.join([pe.lookup(l) for l in string.ascii_lowercase])
+ >>> cat([pe.lookup(l) for l in string.ascii_lowercase])
'udhbfejcpgmokrliwntsayqzvx'
>>> pe.lookup('A')
''
--- /dev/null
+"""A set of functions to break the ciphers give in ciphers.py.
+"""
+
+import string
+import collections
+import norms
+import logging
+import random
+import math
+from itertools import starmap
+from segment import segment
+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 *
+
+# To time a run:
+#
+# import timeit
+# c5a = open('2012/5a.ciphertext', 'r').read()
+# 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)
+
+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', <KeywordWrapAlphabet.from_last: 2>), -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', <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', -52.947271216...)
+ """
+ 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', -307.5473096791...)
+ """
+ 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])
+ 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_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(sanitised_message, key_length)
+ key = cat([chr(-caesar_break(s)[0] % 26 + ord('a'))
+ 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 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])
+
+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), <AmscoFillStyle.continuous: 1>), -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), <AmscoFillStyle.continuous: 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):
+
+ all_matrices = [np.matrix(list(m))
+ for m in itertools.product([list(r)
+ for r in itertools.product(range(26), repeat=matrix_size)],
+ repeat=matrix_size)]
+ valid_matrices = [m for m, d in
+ zip(all_matrices, (int(round(linalg.det(m))) for m in all_matrices))
+ if d != 0
+ if d % 2 != 0
+ if d % 13 != 0 ]
+ with Pool() as pool:
+ helper_args = [(message, matrix, fitness)
+ for matrix in valid_matrices]
+ # Gotcha: the helper function here needs to be defined at the top level
+ # (limitation of Pool.starmap)
+ breaks = pool.starmap(hill_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 hill_break_worker(message, matrix, fitness):
+ plaintext = hill_decipher(matrix, message)
+ fit = fitness(plaintext)
+ logger.debug('Hill cipher break attempt using key {0} gives fit of '
+ '{1} and decrypt starting: {2}'.format(matrix,
+ fit, sanitise(plaintext)[:50]))
+ return matrix, fit
+
+def bifid_break_mp(message, wordlist=keywords, fitness=Pletters,
+ 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>), -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>), -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(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, fitness):
+ plaintext = bifid_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 pocket_enigma_break_by_crib(message, wheel_spec, crib, crib_position):
+ """Break a pocket enigma using a crib (some plaintext that's expected to
+ be in a certain position). Returns a list of possible starting wheel
+ positions that could produce the crib.
+
+ >>> pocket_enigma_break_by_crib('kzpjlzmoga', 1, 'h', 0)
+ ['a', 'f', 'q']
+ >>> pocket_enigma_break_by_crib('kzpjlzmoga', 1, 'he', 0)
+ ['a']
+ >>> pocket_enigma_break_by_crib('kzpjlzmoga', 1, 'll', 2)
+ ['a']
+ >>> pocket_enigma_break_by_crib('kzpjlzmoga', 1, 'l', 2)
+ ['a']
+ >>> pocket_enigma_break_by_crib('kzpjlzmoga', 1, 'l', 3)
+ ['a', 'j', 'n']
+ >>> pocket_enigma_break_by_crib('aaaaa', 1, 'l', 3)
+ []
+ """
+ pe = PocketEnigma(wheel=wheel_spec)
+ possible_positions = []
+ for p in string.ascii_lowercase:
+ pe.set_position(p)
+ plaintext = pe.decipher(message)
+ if plaintext[crib_position:crib_position+len(crib)] == crib:
+ possible_positions += [p]
+ return possible_positions
+
+
+def plot_frequency_histogram(freqs, sort_key=None):
+ 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, key=sort_key))
+ f.show()
+
+
+if __name__ == "__main__":
+ import doctest
+ doctest.testmod()
projects / cipher-training.git / commitdiff