import string
import collections
-import logging
import math
-from itertools import zip_longest, cycle, chain
+from enum import Enum
+from itertools import zip_longest, cycle, chain, count
+import numpy as np
+from numpy import matrix
+from numpy import linalg
from language_models import *
-
-logger = logging.getLogger(__name__)
-logger.addHandler(logging.FileHandler('cipher.log'))
-logger.setLevel(logging.WARNING)
-#logger.setLevel(logging.INFO)
-#logger.setLevel(logging.DEBUG)
-
-
-modular_division_table = [[0]*26 for _ in range(26)]
-for a in range(26):
- for b in range(26):
- c = (a * b) % 26
- modular_division_table[b][c] = a
-
-
-def ngrams(text, n):
- """Returns all n-grams of a text
-
- >>> ngrams(sanitise('the quick brown fox'), 2) # doctest: +NORMALIZE_WHITESPACE
- ['th', 'he', 'eq', 'qu', 'ui', 'ic', 'ck', 'kb', 'br', 'ro', 'ow', 'wn',
- 'nf', 'fo', 'ox']
- >>> ngrams(sanitise('the quick brown fox'), 4) # doctest: +NORMALIZE_WHITESPACE
- ['theq', 'hequ', 'equi', 'quic', 'uick', 'ickb', 'ckbr', 'kbro', 'brow',
- 'rown', 'ownf', 'wnfo', 'nfox']
+import pprint
+
+
+
+from utilities import *
+from segment import *
+
+from caesar import *
+from affine import *
+from keyword import *
+from polybius import *
+from column_transposition import *
+from railfence import *
+
+
+def make_cadenus_keycolumn(doubled_letters = 'vw', start='a', reverse=False):
+ """Makes the key column for a Cadenus cipher (the column down between the
+ rows of letters)
+
+ >>> make_cadenus_keycolumn()['a']
+ 0
+ >>> make_cadenus_keycolumn()['b']
+ 1
+ >>> make_cadenus_keycolumn()['c']
+ 2
+ >>> make_cadenus_keycolumn()['v']
+ 21
+ >>> make_cadenus_keycolumn()['w']
+ 21
+ >>> make_cadenus_keycolumn()['z']
+ 24
+ >>> make_cadenus_keycolumn(doubled_letters='ij', start='b', reverse=True)['a']
+ 1
+ >>> make_cadenus_keycolumn(doubled_letters='ij', start='b', reverse=True)['b']
+ 0
+ >>> make_cadenus_keycolumn(doubled_letters='ij', start='b', reverse=True)['c']
+ 24
+ >>> make_cadenus_keycolumn(doubled_letters='ij', start='b', reverse=True)['i']
+ 18
+ >>> make_cadenus_keycolumn(doubled_letters='ij', start='b', reverse=True)['j']
+ 18
+ >>> make_cadenus_keycolumn(doubled_letters='ij', start='b', reverse=True)['v']
+ 6
+ >>> make_cadenus_keycolumn(doubled_letters='ij', start='b', reverse=True)['z']
+ 2
"""
- return [text[i:i+n] for i in range(len(text)-n+1)]
-
-def every_nth(text, n, fillvalue=''):
- """Returns n strings, each of which consists of every nth character,
- starting with the 0th, 1st, 2nd, ... (n-1)th character
-
- >>> every_nth(string.ascii_lowercase, 5)
- ['afkpuz', 'bglqv', 'chmrw', 'dinsx', 'ejoty']
- >>> every_nth(string.ascii_lowercase, 1)
- ['abcdefghijklmnopqrstuvwxyz']
- >>> every_nth(string.ascii_lowercase, 26) # doctest: +NORMALIZE_WHITESPACE
- ['a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
- 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z']
- >>> every_nth(string.ascii_lowercase, 5, fillvalue='!')
- ['afkpuz', 'bglqv!', 'chmrw!', 'dinsx!', 'ejoty!']
+ 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 = 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)}
+ keycolumn[doubled_letters[0]] = keycolumn[doubled_letters[1]]
+ return keycolumn
+
+def cadenus_encipher(message, keyword, keycolumn, fillvalue='a'):
+ """Encipher with the Cadenus cipher
+
+ >>> cadenus_encipher(sanitise('Whoever has made a voyage up the Hudson ' \
+ 'must remember the Kaatskill mountains. ' \
+ 'They are a dismembered branch of the great'), \
+ 'wink', \
+ make_cadenus_keycolumn(doubled_letters='vw', start='a', reverse=True))
+ 'antodeleeeuhrsidrbhmhdrrhnimefmthgeaetakseomehetyaasuvoyegrastmmuuaeenabbtpchehtarorikswosmvaleatned'
+ >>> cadenus_encipher(sanitise('a severe limitation on the usefulness of ' \
+ 'the cadenus is that every message must be ' \
+ 'a multiple of twenty-five letters long'), \
+ 'easy', \
+ make_cadenus_keycolumn(doubled_letters='vw', start='a', reverse=True))
+ 'systretomtattlusoatleeesfiyheasdfnmschbhneuvsnpmtofarenuseieeieltarlmentieetogevesitfaisltngeeuvowul'
"""
- split_text = [text[i:i+n] for i in range(0, len(text), n)]
- return [''.join(l) for l in zip_longest(*split_text, fillvalue=fillvalue)]
+ rows = chunks(message, len(message) // 25, fillvalue=fillvalue)
+ columns = zip(*rows)
+ rotated_columns = [col[start:] + col[:start] for start, col in zip([keycolumn[l] for l in keyword], columns)]
+ rotated_rows = zip(*rotated_columns)
+ transpositions = transpositions_of(keyword)
+ transposed = [transpose(r, transpositions) for r in rotated_rows]
+ return cat(chain(*transposed))
-def combine_every_nth(split_text):
- """Reforms a text split into every_nth strings
-
- >>> combine_every_nth(every_nth(string.ascii_lowercase, 5))
- 'abcdefghijklmnopqrstuvwxyz'
- >>> combine_every_nth(every_nth(string.ascii_lowercase, 1))
- 'abcdefghijklmnopqrstuvwxyz'
- >>> combine_every_nth(every_nth(string.ascii_lowercase, 26))
- 'abcdefghijklmnopqrstuvwxyz'
+def cadenus_decipher(message, keyword, keycolumn, fillvalue='a'):
+ """
+ >>> cadenus_decipher('antodeleeeuhrsidrbhmhdrrhnimefmthgeaetakseomehetyaa' \
+ 'suvoyegrastmmuuaeenabbtpchehtarorikswosmvaleatned', \
+ 'wink', \
+ make_cadenus_keycolumn(reverse=True))
+ 'whoeverhasmadeavoyageupthehudsonmustrememberthekaatskillmountainstheyareadismemberedbranchofthegreat'
+ >>> cadenus_decipher('systretomtattlusoatleeesfiyheasdfnmschbhneuvsnpmtof' \
+ 'arenuseieeieltarlmentieetogevesitfaisltngeeuvowul', \
+ 'easy', \
+ make_cadenus_keycolumn(reverse=True))
+ 'aseverelimitationontheusefulnessofthecadenusisthateverymessagemustbeamultipleoftwentyfiveletterslong'
"""
- return ''.join([''.join(l)
- for l in zip_longest(*split_text, fillvalue='')])
-
-def chunks(text, n, fillvalue=None):
- """Split a text into chunks of n characters
-
- >>> chunks('abcdefghi', 3)
- ['abc', 'def', 'ghi']
- >>> chunks('abcdefghi', 4)
- ['abcd', 'efgh', 'i']
- >>> chunks('abcdefghi', 4, fillvalue='!')
- ['abcd', 'efgh', 'i!!!']
+ rows = chunks(message, len(message) // 25, fillvalue=fillvalue)
+ transpositions = transpositions_of(keyword)
+ untransposed_rows = [untranspose(r, transpositions) for r in rows]
+ columns = zip(*untransposed_rows)
+ 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 cat(chain(*rotated_rows))
+
+
+def hill_encipher(matrix, message_letters, fillvalue='a'):
+ """Hill cipher
+
+ >>> hill_encipher(np.matrix([[7,8], [11,11]]), 'hellothere')
+ 'drjiqzdrvx'
+ >>> hill_encipher(np.matrix([[6, 24, 1], [13, 16, 10], [20, 17, 15]]), \
+ 'hello there')
+ 'tfjflpznvyac'
"""
- if fillvalue:
- padding = fillvalue[0] * (n - len(text) % n)
+ n = len(matrix)
+ sanitised_message = sanitise(message_letters)
+ if len(sanitised_message) % n != 0:
+ padding = fillvalue[0] * (n - len(sanitised_message) % n)
else:
padding = ''
- return [(text+padding)[i:i+n] for i in range(0, len(text), n)]
-
-def transpose(items, transposition):
- """Moves items around according to the given transposition
-
- >>> transpose(['a', 'b', 'c', 'd'], (0,1,2,3))
- ['a', 'b', 'c', 'd']
- >>> transpose(['a', 'b', 'c', 'd'], (3,1,2,0))
- ['d', 'b', 'c', 'a']
- >>> transpose([10,11,12,13,14,15], (3,2,4,1,5,0))
- [13, 12, 14, 11, 15, 10]
+ message = [pos(c) for c in sanitised_message + padding]
+ message_chunks = [message[i:i+n] for i in range(0, len(message), n)]
+ # message_chunks = chunks(message, len(matrix), fillvalue=None)
+ enciphered_chunks = [((matrix * np.matrix(c).T).T).tolist()[0]
+ for c in message_chunks]
+ return cat([unpos(round(l))
+ for l in sum(enciphered_chunks, [])])
+
+def hill_decipher(matrix, message, fillvalue='a'):
+ """Hill cipher
+
+ >>> hill_decipher(np.matrix([[7,8], [11,11]]), 'drjiqzdrvx')
+ 'hellothere'
+ >>> hill_decipher(np.matrix([[6, 24, 1], [13, 16, 10], [20, 17, 15]]), \
+ 'tfjflpznvyac')
+ 'hellothereaa'
"""
- transposed = [''] * len(transposition)
- for p, t in enumerate(transposition):
- transposed[p] = items[t]
- return transposed
+ adjoint = linalg.det(matrix)*linalg.inv(matrix)
+ inverse_determinant = modular_division_table[int(round(linalg.det(matrix))) % 26][1]
+ inverse_matrix = (inverse_determinant * adjoint) % 26
+ return hill_encipher(inverse_matrix, message, fillvalue)
-def untranspose(items, transposition):
- """Undoes a transpose
-
- >>> untranspose(['a', 'b', 'c', 'd'], [0,1,2,3])
- ['a', 'b', 'c', 'd']
- >>> untranspose(['d', 'b', 'c', 'a'], [3,1,2,0])
- ['a', 'b', 'c', 'd']
- >>> untranspose([13, 12, 14, 11, 15, 10], [3,2,4,1,5,0])
- [10, 11, 12, 13, 14, 15]
- """
- transposed = [''] * len(transposition)
- for p, t in enumerate(transposition):
- transposed[t] = items[p]
- return transposed
-
-def deduplicate(text):
- return list(collections.OrderedDict.fromkeys(text))
-
-
-def caesar_encipher_letter(letter, shift):
- """Encipher a letter, given a shift amount
-
- >>> caesar_encipher_letter('a', 1)
- 'b'
- >>> caesar_encipher_letter('a', 2)
- 'c'
- >>> caesar_encipher_letter('b', 2)
- 'd'
- >>> caesar_encipher_letter('x', 2)
- 'z'
- >>> caesar_encipher_letter('y', 2)
- 'a'
- >>> caesar_encipher_letter('z', 2)
- 'b'
- >>> caesar_encipher_letter('z', -1)
- 'y'
- >>> caesar_encipher_letter('a', -1)
- 'z'
- """
- 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
-def caesar_decipher_letter(letter, shift):
- """Decipher a letter, given a shift amount
-
- >>> caesar_decipher_letter('b', 1)
- 'a'
- >>> caesar_decipher_letter('b', 2)
- 'z'
- """
- return caesar_encipher_letter(letter, -shift)
+# Where each piece of text ends up in the AMSCO transpositon cipher.
+# 'index' shows where the slice appears in the plaintext, with the slice
+# from 'start' to 'end'
+AmscoSlice = collections.namedtuple('AmscoSlice', ['index', 'start', 'end'])
-def caesar_encipher(message, shift):
- """Encipher a message with the Caesar cipher of given shift
-
- >>> caesar_encipher('abc', 1)
- 'bcd'
- >>> caesar_encipher('abc', 2)
- 'cde'
- >>> caesar_encipher('abcxyz', 2)
- 'cdezab'
- >>> caesar_encipher('ab cx yz', 2)
- 'cd ez ab'
- """
- enciphered = [caesar_encipher_letter(l, shift) for l in message]
- return ''.join(enciphered)
+class AmscoFillStyle(Enum):
+ continuous = 1
+ same_each_row = 2
+ reverse_each_row = 3
-def caesar_decipher(message, shift):
- """Encipher a message with the Caesar cipher of given shift
-
- >>> caesar_decipher('bcd', 1)
- 'abc'
- >>> caesar_decipher('cde', 2)
- 'abc'
- >>> caesar_decipher('cd ez ab', 2)
- 'ab cx yz'
+def amsco_transposition_positions(message, keyword,
+ fillpattern=(1, 2),
+ fillstyle=AmscoFillStyle.continuous,
+ fillcolumnwise=False,
+ emptycolumnwise=True):
+ """Creates the grid for the AMSCO transposition cipher. Each element in the
+ grid shows the index of that slice and the start and end positions of the
+ plaintext that go to make it up.
+
+ >>> amsco_transposition_positions(string.ascii_lowercase, 'freddy', \
+ fillpattern=(1, 2)) # doctest: +NORMALIZE_WHITESPACE
+ [[AmscoSlice(index=3, start=4, end=6),
+ AmscoSlice(index=2, start=3, end=4),
+ AmscoSlice(index=0, start=0, end=1),
+ AmscoSlice(index=1, start=1, end=3),
+ AmscoSlice(index=4, start=6, end=7)],
+ [AmscoSlice(index=8, start=12, end=13),
+ AmscoSlice(index=7, start=10, end=12),
+ AmscoSlice(index=5, start=7, end=9),
+ AmscoSlice(index=6, start=9, end=10),
+ AmscoSlice(index=9, start=13, end=15)],
+ [AmscoSlice(index=13, start=19, end=21),
+ AmscoSlice(index=12, start=18, end=19),
+ AmscoSlice(index=10, start=15, end=16),
+ AmscoSlice(index=11, start=16, end=18),
+ AmscoSlice(index=14, start=21, end=22)],
+ [AmscoSlice(index=18, start=27, end=28),
+ AmscoSlice(index=17, start=25, end=27),
+ AmscoSlice(index=15, start=22, end=24),
+ AmscoSlice(index=16, start=24, end=25),
+ AmscoSlice(index=19, start=28, end=30)]]
"""
- return caesar_encipher(message, -shift)
-
-def affine_encipher_letter(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'
+ transpositions = transpositions_of(keyword)
+ fill_iterator = cycle(fillpattern)
+ indices = count()
+ message_length = len(message)
+
+ current_position = 0
+ grid = []
+ current_fillpattern = fillpattern
+ while current_position < message_length:
+ row = []
+ if fillstyle == AmscoFillStyle.same_each_row:
+ fill_iterator = cycle(fillpattern)
+ if fillstyle == AmscoFillStyle.reverse_each_row:
+ fill_iterator = cycle(current_fillpattern)
+ for _ in range(len(transpositions)):
+ index = next(indices)
+ gap = next(fill_iterator)
+ row += [AmscoSlice(index, current_position, current_position + gap)]
+ current_position += gap
+ grid += [row]
+ if fillstyle == AmscoFillStyle.reverse_each_row:
+ current_fillpattern = list(reversed(current_fillpattern))
+ return [transpose(r, transpositions) for r in grid]
+
+def amsco_transposition_encipher(message, keyword,
+ fillpattern=(1,2), fillstyle=AmscoFillStyle.reverse_each_row):
+ """AMSCO transposition encipher.
+
+ >>> amsco_transposition_encipher('hellothere', 'abc', fillpattern=(1, 2))
+ 'hoteelhler'
+ >>> amsco_transposition_encipher('hellothere', 'abc', fillpattern=(2, 1))
+ 'hetelhelor'
+ >>> amsco_transposition_encipher('hellothere', 'acb', fillpattern=(1, 2))
+ 'hotelerelh'
+ >>> amsco_transposition_encipher('hellothere', 'acb', fillpattern=(2, 1))
+ 'hetelorlhe'
+ >>> amsco_transposition_encipher('hereissometexttoencipher', 'encode')
+ 'etecstthhomoerereenisxip'
+ >>> amsco_transposition_encipher('hereissometexttoencipher', 'cipher', fillpattern=(1, 2))
+ 'hetcsoeisterereipexthomn'
+ >>> amsco_transposition_encipher('hereissometexttoencipher', 'cipher', fillpattern=(1, 2), fillstyle=AmscoFillStyle.continuous)
+ 'hecsoisttererteipexhomen'
+ >>> amsco_transposition_encipher('hereissometexttoencipher', 'cipher', fillpattern=(2, 1))
+ 'heecisoosttrrtepeixhemen'
+ >>> amsco_transposition_encipher('hereissometexttoencipher', 'cipher', fillpattern=(1, 3, 2))
+ 'hxtomephescieretoeisnter'
+ >>> amsco_transposition_encipher('hereissometexttoencipher', 'cipher', fillpattern=(1, 3, 2), fillstyle=AmscoFillStyle.continuous)
+ 'hxomeiphscerettoisenteer'
"""
- 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
+ grid = amsco_transposition_positions(message, keyword,
+ fillpattern=fillpattern, fillstyle=fillstyle)
+ ct_as_grid = [[message[s.start:s.end] for s in r] for r in grid]
+ return combine_every_nth(ct_as_grid)
-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'
- """
- 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
-def affine_encipher(message, multiplier=1, adder=0, one_based=True):
- """Encipher a message
-
- >>> affine_encipher('hours passed during which jerico tried every ' \
- 'trick he could think of', 15, 22, True)
- 'lmyfu bkuusd dyfaxw claol psfaom jfasd snsfg jfaoe ls omytd jlaxe mh'
+def amsco_transposition_decipher(message, keyword,
+ fillpattern=(1,2), fillstyle=AmscoFillStyle.reverse_each_row):
+ """AMSCO transposition decipher
+
+ >>> amsco_transposition_decipher('hoteelhler', 'abc', fillpattern=(1, 2))
+ 'hellothere'
+ >>> amsco_transposition_decipher('hetelhelor', 'abc', fillpattern=(2, 1))
+ 'hellothere'
+ >>> amsco_transposition_decipher('hotelerelh', 'acb', fillpattern=(1, 2))
+ 'hellothere'
+ >>> amsco_transposition_decipher('hetelorlhe', 'acb', fillpattern=(2, 1))
+ 'hellothere'
+ >>> amsco_transposition_decipher('etecstthhomoerereenisxip', 'encode')
+ 'hereissometexttoencipher'
+ >>> amsco_transposition_decipher('hetcsoeisterereipexthomn', 'cipher', fillpattern=(1, 2))
+ 'hereissometexttoencipher'
+ >>> amsco_transposition_decipher('hecsoisttererteipexhomen', 'cipher', fillpattern=(1, 2), fillstyle=AmscoFillStyle.continuous)
+ 'hereissometexttoencipher'
+ >>> amsco_transposition_decipher('heecisoosttrrtepeixhemen', 'cipher', fillpattern=(2, 1))
+ 'hereissometexttoencipher'
+ >>> amsco_transposition_decipher('hxtomephescieretoeisnter', 'cipher', fillpattern=(1, 3, 2))
+ 'hereissometexttoencipher'
+ >>> amsco_transposition_decipher('hxomeiphscerettoisenteer', 'cipher', fillpattern=(1, 3, 2), fillstyle=AmscoFillStyle.continuous)
+ 'hereissometexttoencipher'
"""
- enciphered = [affine_encipher_letter(l, multiplier, adder, one_based)
- for l in message]
- return ''.join(enciphered)
-def affine_decipher(message, multiplier=1, adder=0, one_based=True):
- """Decipher a message
-
- >>> affine_decipher('lmyfu bkuusd dyfaxw claol psfaom jfasd snsfg ' \
- 'jfaoe ls omytd jlaxe mh', 15, 22, True)
- 'hours passed during which jerico tried every trick he could think of'
+ grid = amsco_transposition_positions(message, keyword,
+ fillpattern=fillpattern, fillstyle=fillstyle)
+ transposed_sections = [s for c in [l for l in zip(*grid)] for s in c]
+ plaintext_list = [''] * len(transposed_sections)
+ current_pos = 0
+ 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 cat(plaintext_list)
+
+
+def bifid_grid(keyword, wrap_alphabet, letter_mapping):
+ """Create the grids for a Bifid cipher
"""
- enciphered = [affine_decipher_letter(l, multiplier, adder, one_based)
- for l in message]
- return ''.join(enciphered)
-
-
-def keyword_cipher_alphabet_of(keyword, wrap_alphabet=0):
- """Find the cipher alphabet given a keyword.
- wrap_alphabet controls how the rest of the alphabet is added
- after the keyword.
- 0 : from 'a'
- 1 : from the last letter in the sanitised keyword
- 2 : from the largest letter in the sanitised keyword
-
- >>> keyword_cipher_alphabet_of('bayes')
- 'bayescdfghijklmnopqrtuvwxz'
- >>> keyword_cipher_alphabet_of('bayes', 0)
- 'bayescdfghijklmnopqrtuvwxz'
- >>> keyword_cipher_alphabet_of('bayes', 1)
- 'bayestuvwxzcdfghijklmnopqr'
- >>> keyword_cipher_alphabet_of('bayes', 2)
- 'bayeszcdfghijklmnopqrtuvwx'
+ 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'
"""
- if wrap_alphabet == 0:
- cipher_alphabet = ''.join(deduplicate(sanitise(keyword) +
- string.ascii_lowercase))
+ 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:
- if wrap_alphabet == 1:
- last_keyword_letter = deduplicate(sanitise(keyword))[-1]
- else:
- last_keyword_letter = sorted(sanitise(keyword))[-1]
- last_keyword_position = string.ascii_lowercase.find(
- last_keyword_letter) + 1
- cipher_alphabet = ''.join(
- deduplicate(sanitise(keyword) +
- string.ascii_lowercase[last_keyword_position:] +
- string.ascii_lowercase))
- return cipher_alphabet
-
-
-def keyword_encipher(message, keyword, wrap_alphabet=0):
- """Enciphers a message with a keyword substitution cipher.
- wrap_alphabet controls how the rest of the alphabet is added
- after the keyword.
- 0 : from 'a'
- 1 : from the last letter in the sanitised keyword
- 2 : from the largest letter in the sanitised keyword
-
- >>> keyword_encipher('test message', 'bayes')
- 'rsqr ksqqbds'
- >>> keyword_encipher('test message', 'bayes', 0)
- 'rsqr ksqqbds'
- >>> keyword_encipher('test message', 'bayes', 1)
- 'lskl dskkbus'
- >>> keyword_encipher('test message', 'bayes', 2)
- 'qspq jsppbcs'
- """
- cipher_alphabet = keyword_cipher_alphabet_of(keyword, wrap_alphabet)
- cipher_translation = ''.maketrans(string.ascii_lowercase, cipher_alphabet)
- return message.lower().translate(cipher_translation)
-
-def keyword_decipher(message, keyword, wrap_alphabet=0):
- """Deciphers a message with a keyword substitution cipher.
- wrap_alphabet controls how the rest of the alphabet is added
- after the keyword.
- 0 : from 'a'
- 1 : from the last letter in the sanitised keyword
- 2 : from the largest letter in the sanitised keyword
+ chunked_pairs = [pairs0]
- >>> keyword_decipher('rsqr ksqqbds', 'bayes')
- 'test message'
- >>> keyword_decipher('rsqr ksqqbds', 'bayes', 0)
- 'test message'
- >>> keyword_decipher('lskl dskkbus', 'bayes', 1)
- 'test message'
- >>> keyword_decipher('qspq jsppbcs', 'bayes', 2)
- 'test message'
- """
- cipher_alphabet = keyword_cipher_alphabet_of(keyword, wrap_alphabet)
- cipher_translation = ''.maketrans(cipher_alphabet, string.ascii_lowercase)
- return message.lower().translate(cipher_translation)
-
-
-def vigenere_encipher(message, keyword):
- """Vigenere encipher
+ 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)
- >>> vigenere_encipher('hello', 'abc')
- 'hfnlp'
- """
- 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])
-def vigenere_decipher(message, keyword):
- """Vigenere decipher
+def bifid_decipher(message, keyword, wrap_alphabet=KeywordWrapAlphabet.from_a,
+ letter_mapping=None, period=None, fillvalue=None):
+ """Decipher with bifid cipher
- >>> vigenere_decipher('hfnlp', 'abc')
- 'hello'
+ >>> bifid_decipher('ibidonhprm', 'iguana')
+ 'indiaielly'
+ >>> bifid_decipher("ibnhgaqltm", 'iguana', period=4)
+ 'indiacurry'
+ >>> bifid_decipher("ibnhgaqltzml", 'iguana', period=4)
+ 'indiacurryxx'
"""
- 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])
-
-beaufort_encipher=vigenere_decipher
-beaufort_decipher=vigenere_encipher
+ 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)
-def transpositions_of(keyword):
- """Finds the transpostions given by a keyword. For instance, the keyword
- 'clever' rearranges to 'celrv', so the first column (0) stays first, the
- second column (1) moves to third, the third column (2) moves to second,
- and so on.
- If passed a tuple, assume it's already a transposition and just return it.
+def autokey_encipher(message, keyword):
+ """Encipher with the autokey cipher
- >>> transpositions_of('clever')
- (0, 2, 1, 4, 3)
- >>> transpositions_of('fred')
- (3, 2, 0, 1)
- >>> transpositions_of((3, 2, 0, 1))
- (3, 2, 0, 1)
+ >>> autokey_encipher('meetatthefountain', 'kilt')
+ 'wmpmmxxaeyhbryoca'
"""
- if isinstance(keyword, tuple):
- return keyword
- else:
- key = deduplicate(keyword)
- transpositions = tuple(key.index(l) for l in sorted(key))
- return transpositions
-
-def pad(message_len, group_len, fillvalue):
- padding_length = group_len - message_len % group_len
- if padding_length == group_len: padding_length = 0
- padding = ''
- for i in range(padding_length):
- if callable(fillvalue):
- padding += fillvalue()
- else:
- padding += fillvalue
- return padding
+ shifts = [pos(l) for l in keyword + message]
+ pairs = zip(message, shifts)
+ return cat([caesar_encipher_letter(l, k) for l, k in pairs])
-def column_transposition_encipher(message, keyword, fillvalue=' ',
- fillcolumnwise=False,
- emptycolumnwise=False):
- """Enciphers using the column transposition cipher.
- Message is padded to allow all rows to be the same length.
-
- >>> column_transposition_encipher('hellothere', 'abcdef', fillcolumnwise=True)
- 'hlohr eltee '
- >>> column_transposition_encipher('hellothere', 'abcdef', fillcolumnwise=True, emptycolumnwise=True)
- 'hellothere '
- >>> column_transposition_encipher('hellothere', 'abcdef')
- 'hellothere '
- >>> column_transposition_encipher('hellothere', 'abcde')
- 'hellothere'
- >>> column_transposition_encipher('hellothere', 'abcde', fillcolumnwise=True, emptycolumnwise=True)
- 'hellothere'
- >>> column_transposition_encipher('hellothere', 'abcde', fillcolumnwise=True, emptycolumnwise=False)
- 'hlohreltee'
- >>> column_transposition_encipher('hellothere', 'abcde', fillcolumnwise=False, emptycolumnwise=True)
- 'htehlelroe'
- >>> column_transposition_encipher('hellothere', 'abcde', fillcolumnwise=False, emptycolumnwise=False)
- 'hellothere'
- >>> column_transposition_encipher('hellothere', 'clever', fillcolumnwise=True, emptycolumnwise=True)
- 'heotllrehe'
- >>> column_transposition_encipher('hellothere', 'clever', fillcolumnwise=True, emptycolumnwise=False)
- 'holrhetlee'
- >>> column_transposition_encipher('hellothere', 'clever', fillcolumnwise=False, emptycolumnwise=True)
- 'htleehoelr'
- >>> column_transposition_encipher('hellothere', 'clever', fillcolumnwise=False, emptycolumnwise=False)
- 'hleolteher'
- >>> column_transposition_encipher('hellothere', 'cleverly')
- 'hleolthre e '
- >>> column_transposition_encipher('hellothere', 'cleverly', fillvalue='!')
- 'hleolthre!e!'
- >>> column_transposition_encipher('hellothere', 'cleverly', fillvalue=lambda: '*')
- 'hleolthre*e*'
- """
- transpositions = transpositions_of(keyword)
- message += pad(len(message), len(transpositions), fillvalue)
- if fillcolumnwise:
- rows = every_nth(message, len(message) // len(transpositions))
- else:
- rows = chunks(message, len(transpositions))
- transposed = [transpose(r, transpositions) for r in rows]
- if emptycolumnwise:
- return combine_every_nth(transposed)
- else:
- return ''.join(chain(*transposed))
-
-def column_transposition_decipher(message, keyword, fillvalue=' ',
- fillcolumnwise=False,
- emptycolumnwise=False):
- """Deciphers using the column transposition cipher.
- Message is padded to allow all rows to be the same length.
+def autokey_decipher(ciphertext, keyword):
+ """Decipher with the autokey cipher
- >>> column_transposition_decipher('hellothere', 'abcde', fillcolumnwise=True, emptycolumnwise=True)
- 'hellothere'
- >>> column_transposition_decipher('hlohreltee', 'abcde', fillcolumnwise=True, emptycolumnwise=False)
- 'hellothere'
- >>> column_transposition_decipher('htehlelroe', 'abcde', fillcolumnwise=False, emptycolumnwise=True)
- 'hellothere'
- >>> column_transposition_decipher('hellothere', 'abcde', fillcolumnwise=False, emptycolumnwise=False)
- 'hellothere'
- >>> column_transposition_decipher('heotllrehe', 'clever', fillcolumnwise=True, emptycolumnwise=True)
- 'hellothere'
- >>> column_transposition_decipher('holrhetlee', 'clever', fillcolumnwise=True, emptycolumnwise=False)
- 'hellothere'
- >>> column_transposition_decipher('htleehoelr', 'clever', fillcolumnwise=False, emptycolumnwise=True)
- 'hellothere'
- >>> column_transposition_decipher('hleolteher', 'clever', fillcolumnwise=False, emptycolumnwise=False)
- 'hellothere'
- """
- transpositions = transpositions_of(keyword)
- message += pad(len(message), len(transpositions), '*')
- if emptycolumnwise:
- rows = every_nth(message, len(message) // len(transpositions))
- else:
- rows = chunks(message, len(transpositions))
- untransposed = [untranspose(r, transpositions) for r in rows]
- if fillcolumnwise:
- return combine_every_nth(untransposed)
- else:
- return ''.join(chain(*untransposed))
-
-def scytale_encipher(message, rows, fillvalue=' '):
- """Enciphers using the scytale transposition cipher.
- Message is padded with spaces to allow all rows to be the same length.
-
- >>> scytale_encipher('thequickbrownfox', 3)
- 'tcnhkfeboqrxuo iw '
- >>> scytale_encipher('thequickbrownfox', 4)
- 'tubnhirfecooqkwx'
- >>> scytale_encipher('thequickbrownfox', 5)
- 'tubnhirfecooqkwx'
- >>> scytale_encipher('thequickbrownfox', 6)
- 'tqcrnxhukof eibwo '
- >>> scytale_encipher('thequickbrownfox', 7)
- 'tqcrnxhukof eibwo '
+ >>> autokey_decipher('wmpmmxxaeyhbryoca', 'kilt')
+ 'meetatthefountain'
"""
- transpositions = [i for i in range(math.ceil(len(message) / rows))]
- return column_transposition_encipher(message, transpositions,
- fillcolumnwise=False, emptycolumnwise=True)
-
-def scytale_decipher(message, rows):
- """Deciphers using the scytale transposition cipher.
- Assumes the message is padded so that all rows are the same length.
-
- >>> scytale_decipher('tcnhkfeboqrxuo iw ', 3)
- 'thequickbrownfox '
- >>> scytale_decipher('tubnhirfecooqkwx', 4)
- 'thequickbrownfox'
- >>> scytale_decipher('tubnhirfecooqkwx', 5)
- 'thequickbrownfox'
- >>> scytale_decipher('tqcrnxhukof eibwo ', 6)
- 'thequickbrownfox '
- >>> scytale_decipher('tqcrnxhukof eibwo ', 7)
- 'thequickbrownfox '
+ plaintext = []
+ keys = list(keyword)
+ for c in ciphertext:
+ plaintext_letter = caesar_decipher_letter(c, pos(keys[0]))
+ plaintext += [plaintext_letter]
+ keys = keys[1:] + [plaintext_letter]
+ return cat(plaintext)
+
+
+class PocketEnigma(object):
+ """A pocket enigma machine
+ The wheel is internally represented as a 26-element list self.wheel_map,
+ where wheel_map[i] == j shows that the position i places on from the arrow
+ maps to the position j places on.
"""
- transpositions = [i for i in range(math.ceil(len(message) / rows))]
- return column_transposition_decipher(message, transpositions,
- fillcolumnwise=False, emptycolumnwise=True)
+ def __init__(self, wheel=1, position='a'):
+ """initialise the pocket enigma, including which wheel to use and the
+ starting position of the wheel.
+
+ The wheel is either 1 or 2 (the predefined wheels) or a list of letter
+ pairs.
+
+ The position is the letter pointed to by the arrow on the wheel.
+
+ >>> pe.wheel_map
+ [25, 4, 23, 10, 1, 7, 9, 5, 12, 6, 3, 17, 8, 14, 13, 21, 19, 11, 20, 16, 18, 15, 24, 2, 22, 0]
+ >>> pe.position
+ 0
+ """
+ self.wheel1 = [('a', 'z'), ('b', 'e'), ('c', 'x'), ('d', 'k'),
+ ('f', 'h'), ('g', 'j'), ('i', 'm'), ('l', 'r'), ('n', 'o'),
+ ('p', 'v'), ('q', 't'), ('s', 'u'), ('w', 'y')]
+ self.wheel2 = [('a', 'c'), ('b', 'd'), ('e', 'w'), ('f', 'i'),
+ ('g', 'p'), ('h', 'm'), ('j', 'k'), ('l', 'n'), ('o', 'q'),
+ ('r', 'z'), ('s', 'u'), ('t', 'v'), ('x', 'y')]
+ if wheel == 1:
+ self.make_wheel_map(self.wheel1)
+ elif wheel == 2:
+ self.make_wheel_map(self.wheel2)
+ else:
+ self.validate_wheel_spec(wheel)
+ self.make_wheel_map(wheel)
+ if position in string.ascii_lowercase:
+ self.position = pos(position)
+ else:
+ self.position = position
+
+ def make_wheel_map(self, wheel_spec):
+ """Expands a wheel specification from a list of letter-letter pairs
+ into a full wheel_map.
+
+ >>> pe.make_wheel_map(pe.wheel2)
+ [2, 3, 0, 1, 22, 8, 15, 12, 5, 10, 9, 13, 7, 11, 16, 6, 14, 25, 20, 21, 18, 19, 4, 24, 23, 17]
+ """
+ self.validate_wheel_spec(wheel_spec)
+ self.wheel_map = [0] * 26
+ for p in wheel_spec:
+ self.wheel_map[pos(p[0])] = pos(p[1])
+ self.wheel_map[pos(p[1])] = pos(p[0])
+ return self.wheel_map
+
+ def validate_wheel_spec(self, wheel_spec):
+ """Validates that a wheel specificaiton will turn into a valid wheel
+ map.
+
+ >>> pe.validate_wheel_spec([])
+ Traceback (most recent call last):
+ ...
+ ValueError: Wheel specification has 0 pairs, requires 13
+ >>> pe.validate_wheel_spec([('a', 'b', 'c')]*13)
+ Traceback (most recent call last):
+ ...
+ ValueError: Not all mappings in wheel specificationhave two elements
+ >>> pe.validate_wheel_spec([('a', 'b')]*13)
+ Traceback (most recent call last):
+ ...
+ ValueError: Wheel specification does not contain 26 letters
+ """
+ if len(wheel_spec) != 13:
+ raise ValueError("Wheel specification has {} pairs, requires 13".
+ format(len(wheel_spec)))
+ for p in wheel_spec:
+ if len(p) != 2:
+ raise ValueError("Not all mappings in wheel specification"
+ "have two elements")
+ if len(set([p[0] for p in wheel_spec] +
+ [p[1] for p in wheel_spec])) != 26:
+ raise ValueError("Wheel specification does not contain 26 letters")
+
+ def encipher_letter(self, letter):
+ """Enciphers a single letter, by advancing the wheel before looking up
+ the letter on the wheel.
+
+ >>> pe.set_position('f')
+ 5
+ >>> pe.encipher_letter('k')
+ 'h'
+ """
+ self.advance()
+ return self.lookup(letter)
+ decipher_letter = encipher_letter
+
+ def lookup(self, letter):
+ """Look up what a letter enciphers to, without turning the wheel.
+
+ >>> pe.set_position('f')
+ 5
+ >>> cat([pe.lookup(l) for l in string.ascii_lowercase])
+ 'udhbfejcpgmokrliwntsayqzvx'
+ >>> pe.lookup('A')
+ ''
+ """
+ if letter in string.ascii_lowercase:
+ return unpos(
+ (self.wheel_map[(pos(letter) - self.position) % 26] +
+ self.position))
+ else:
+ return ''
+
+ def advance(self):
+ """Advances the wheel one position.
+
+ >>> pe.set_position('f')
+ 5
+ >>> pe.advance()
+ 6
+ """
+ self.position = (self.position + 1) % 26
+ return self.position
+
+ def encipher(self, message, starting_position=None):
+ """Enciphers a whole message.
+
+ >>> pe.set_position('f')
+ 5
+ >>> pe.encipher('helloworld')
+ 'kjsglcjoqc'
+ >>> pe.set_position('f')
+ 5
+ >>> pe.encipher('kjsglcjoqc')
+ 'helloworld'
+ >>> pe.encipher('helloworld', starting_position = 'x')
+ 'egrekthnnf'
+ """
+ if starting_position:
+ self.set_position(starting_position)
+ transformed = ''
+ for l in message:
+ transformed += self.encipher_letter(l)
+ return transformed
+ decipher = encipher
+
+ def set_position(self, position):
+ """Sets the position of the wheel, by specifying the letter the arrow
+ points to.
+
+ >>> pe.set_position('a')
+ 0
+ >>> pe.set_position('m')
+ 12
+ >>> pe.set_position('z')
+ 25
+ """
+ self.position = pos(position)
+ return self.position
if __name__ == "__main__":
import doctest
- doctest.testmod()
+ doctest.testmod(extraglobs={'pe': PocketEnigma(1, 'a')})
projects / cipher-tools.git / blobdiff