X-Git-Url: https://git.njae.me.uk/?a=blobdiff_plain;f=cipher.py;h=1c71b5c205567807332accf8d3fbada74b1c0c28;hb=4e49d9a8c3379d16d1d721a14b072396568ecbcc;hp=7ba5c628d4b6273779765ea3f640b347078a4b4c;hpb=e9ce74d67cf228434b271026b2061f9565202dd4;p=cipher-tools.git diff --git a/cipher.py b/cipher.py index 7ba5c62..1c71b5c 100644 --- a/cipher.py +++ b/cipher.py @@ -7,12 +7,23 @@ import numpy as np 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)] for a in range(26): @@ -125,14 +136,24 @@ def caesar_encipher_letter(accented_letter, shift): >>> 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 @@ -180,49 +201,74 @@ 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 - >>> cat([affine_encipher_letter(l, 3, 5, True) \ - for l in string.ascii_uppercase]) - 'HKNQTWZCFILORUXADGJMPSVYBE' - >>> cat([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 - >>> cat([affine_decipher_letter(l, 3, 5, True) \ - for l in 'HKNQTWZCFILORUXADGJMPSVYBE']) - 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' - >>> cat([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 @@ -897,6 +943,82 @@ def amsco_transposition_decipher(message, keyword, 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 The wheel is internally represented as a 26-element list self.wheel_map,