X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=cipher.py;h=7ba5c628d4b6273779765ea3f640b347078a4b4c;hb=e9ce74d67cf228434b271026b2061f9565202dd4;hp=6cce72543224f02468e8a7609b674d158d238127;hpb=674b12c1ed3d8c4a6007f1744afb7a5fbf90fb6c;p=cipher-tools.git diff --git a/cipher.py b/cipher.py index 6cce725..7ba5c62 100644 --- a/cipher.py +++ b/cipher.py @@ -2,10 +2,18 @@ import string import collections import math from enum import Enum -from itertools import zip_longest, cycle, chain +from itertools import zip_longest, cycle, chain, count +import numpy as np +from numpy import matrix +from numpy import linalg from language_models import * +## Utility functions +cat = ''.join +wcat = ' '.join + + modular_division_table = [[0]*26 for _ in range(26)] for a in range(26): for b in range(26): @@ -28,7 +36,7 @@ def every_nth(text, n, fillvalue=''): ['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 @@ -40,7 +48,7 @@ def combine_every_nth(split_text): >>> 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): @@ -153,7 +161,7 @@ def caesar_encipher(message, shift): '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 @@ -172,10 +180,10 @@ def caesar_decipher(message, 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) \ + >>> cat([affine_encipher_letter(l, 3, 5, True) \ for l in string.ascii_uppercase]) 'HKNQTWZCFILORUXADGJMPSVYBE' - >>> ''.join([affine_encipher_letter(l, 3, 5, False) \ + >>> cat([affine_encipher_letter(l, 3, 5, False) \ for l in string.ascii_uppercase]) 'FILORUXADGJMPSVYBEHKNQTWZC' """ @@ -196,10 +204,10 @@ def affine_encipher_letter(accented_letter, multiplier=1, adder=0, one_based=Tru 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) \ + >>> cat([affine_decipher_letter(l, 3, 5, True) \ for l in 'HKNQTWZCFILORUXADGJMPSVYBE']) 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' - >>> ''.join([affine_decipher_letter(l, 3, 5, False) \ + >>> cat([affine_decipher_letter(l, 3, 5, False) \ for l in 'FILORUXADGJMPSVYBEHKNQTWZC']) 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' """ @@ -227,7 +235,7 @@ def affine_encipher(message, multiplier=1, adder=0, one_based=True): """ 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 @@ -238,7 +246,7 @@ def affine_decipher(message, multiplier=1, adder=0, one_based=True): """ enciphered = [affine_decipher_letter(l, multiplier, adder, one_based) for l in message] - return ''.join(enciphered) + return cat(enciphered) class KeywordWrapAlphabet(Enum): @@ -262,7 +270,7 @@ def keyword_cipher_alphabet_of(keyword, wrap_alphabet=KeywordWrapAlphabet.from_a '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: @@ -271,7 +279,7 @@ def keyword_cipher_alphabet_of(keyword, wrap_alphabet=KeywordWrapAlphabet.from_a 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)) @@ -329,7 +337,7 @@ def vigenere_encipher(message, keyword): """ 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 @@ -339,7 +347,7 @@ def vigenere_decipher(message, keyword): """ 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 @@ -425,7 +433,7 @@ def column_transposition_encipher(message, keyword, fillvalue=' ', 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, @@ -460,7 +468,7 @@ def column_transposition_decipher(message, keyword, fillvalue=' ', 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. @@ -541,14 +549,14 @@ def railfence_encipher(message, height, fillvalue=''): 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. @@ -623,11 +631,270 @@ def railfence_decipher(message, height, fillvalue=''): 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 + 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 + """ + 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' + """ + 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 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' + """ + 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' + """ + n = len(matrix) + sanitised_message = sanitise(message_letters) + if len(sanitised_message) % n != 0: + padding = fillvalue[0] * (n - len(sanitised_message) % n) + else: + padding = '' + message = [ord(c) - ord('a') 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([chr(int(round(l)) % 26 + ord('a')) + 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' + """ + 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) + + +# 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']) + +class AmscoFillStyle(Enum): + continuous = 1 + same_each_row = 2 + reverse_each_row = 3 + +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)]] + """ + 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' + """ + 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 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' + """ + + 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) class PocketEnigma(object): @@ -728,7 +995,7 @@ class PocketEnigma(object): >>> 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') ''