-beaufort_variant_encipher=vigenere_decipher
-beaufort_variant_decipher=vigenere_encipher
-
-
-def polybius_grid(keyword, column_order, row_order, letters_to_merge=None,
- wrap_alphabet=KeywordWrapAlphabet.from_a):
- """Grid for a Polybius cipher, using a keyword to rearrange the
- alphabet.
-
-
- >>> polybius_grid('a', 'abcde', 'abcde')['x'] == ('e', 'c')
- True
- >>> polybius_grid('elephant', 'abcde', 'abcde')['e'] == ('a', 'a')
- True
- >>> polybius_grid('elephant', 'abcde', 'abcde')['b'] == ('b', 'c')
- True
- """
- alphabet = keyword_cipher_alphabet_of(keyword, wrap_alphabet=wrap_alphabet)
- if letters_to_merge is None:
- letters_to_merge = {'j': 'i'}
- grid = {l: k
- for k, l in zip([(c, r) for c in column_order for r in row_order],
- [l for l in alphabet if l not in letters_to_merge])}
- for l in letters_to_merge:
- grid[l] = grid[letters_to_merge[l]]
- return grid
-
-def polybius_reverse_grid(keyword, column_order, row_order, letters_to_merge=None,
- wrap_alphabet=KeywordWrapAlphabet.from_a):
- """Grid for decrypting using a Polybius cipher, using a keyword to
- rearrange the alphabet.
-
- >>> polybius_reverse_grid('a', 'abcde', 'abcde')['e', 'c'] == 'x'
- True
- >>> polybius_reverse_grid('elephant', 'abcde', 'abcde')['a', 'a'] == 'e'
- True
- >>> polybius_reverse_grid('elephant', 'abcde', 'abcde')['b', 'c'] == 'b'
- True
- """
- alphabet = keyword_cipher_alphabet_of(keyword, wrap_alphabet=wrap_alphabet)
- if letters_to_merge is None:
- letters_to_merge = {'j': 'i'}
- grid = {k: l
- for k, l in zip([(c, r) for c in column_order for r in row_order],
- [l for l in alphabet if l not in letters_to_merge])}
- return grid
-
-
-def polybius_flatten(pair, column_first):
- """Convert a series of pairs into a single list of characters"""
- if column_first:
- return str(pair[1]) + str(pair[0])
- else:
- return str(pair[0]) + str(pair[1])
-
-def polybius_encipher(message, keyword, column_order, row_order,
- column_first=False,
- letters_to_merge=None, wrap_alphabet=KeywordWrapAlphabet.from_a):
- """Encipher a message with Polybius cipher, using a keyword to rearrange
- the alphabet
-
-
- >>> polybius_encipher('this is a test message for the ' \
- 'polybius decipherment', 'elephant', \
- [1, 2, 3, 4, 5], [1, 2, 3, 4, 5], \
- wrap_alphabet=KeywordWrapAlphabet.from_last)
- '2214445544551522115522511155551543114252542214111352123234442355411135441314115451112122'
- >>> polybius_encipher('this is a test message for the ' \
- 'polybius decipherment', 'elephant', 'abcde', 'abcde', \
- column_first=False)
- 'bbadccddccddaebbaaddbbceaaddddaecbaacadadcbbadaaacdaabedbcccdeddbeaabdccacadaadcceaababb'
- >>> polybius_encipher('this is a test message for the ' \
- 'polybius decipherment', 'elephant', 'abcde', 'abcde', \
- column_first=True)
- 'bbdaccddccddeabbaaddbbecaaddddeabcaaacadcdbbdaaacaadbadecbccedddebaadbcccadaaacdecaaabbb'
- """
- grid = polybius_grid(keyword, column_order, row_order, letters_to_merge, wrap_alphabet)
- return cat(polybius_flatten(grid[l], column_first)
- for l in message
- if l in grid)
-
-
-def polybius_decipher(message, keyword, column_order, row_order,
- column_first=False,
- letters_to_merge=None, wrap_alphabet=KeywordWrapAlphabet.from_a):
- """Decipher a message with a Polybius cipher, using a keyword to rearrange
- the alphabet
-
- >>> polybius_decipher('bbdaccddccddeabbaaddbbecaaddddeabcaaacadcdbbdaaaca'\
- 'adbadecbccedddebaadbcccadaaacdecaaabbb', 'elephant', 'abcde', 'abcde', \
- column_first=False)
- 'toisisvtestxessvbephktoefhnugiysweqifoekxelt'
-
- >>> polybius_decipher('bbdaccddccddeabbaaddbbecaaddddeabcaaacadcdbbdaaaca'\
- 'adbadecbccedddebaadbcccadaaacdecaaabbb', 'elephant', 'abcde', 'abcde', \
- column_first=True)
- 'thisisatestmessageforthepolybiusdecipherment'
- """
- grid = polybius_reverse_grid(keyword, column_order, row_order, letters_to_merge, wrap_alphabet)
- column_index_type = type(column_order[0])
- row_index_type = type(row_order[0])
- if column_first:
- pairs = [(column_index_type(p[1]), row_index_type(p[0])) for p in chunks(message, 2)]
- else:
- pairs = [(row_index_type(p[0]), column_index_type(p[1])) for p in chunks(message, 2)]
- return cat(grid[p] for p in pairs if p in grid)
-
-
-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.
-
- >>> 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)
- """
- 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
-
-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 cat(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.
-
- >>> 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), fillvalue)
- 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 cat(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)
- 'tubn hirf ecoo qkwx '
- >>> scytale_encipher('thequickbrownfox', 6)
- 'tqcrnxhukof eibwo '
- >>> scytale_encipher('thequickbrownfox', 7)
- 'tqcrnx hukof eibwo '
- """
- # transpositions = [i for i in range(math.ceil(len(message) / rows))]
- # return column_transposition_encipher(message, transpositions,
- # fillvalue=fillvalue, fillcolumnwise=False, emptycolumnwise=True)
- transpositions = [i for i in range(rows)]
- return column_transposition_encipher(message, transpositions,
- fillvalue=fillvalue, fillcolumnwise=True, emptycolumnwise=False)
-
-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('tubn hirf ecoo qkwx ', 5)
- 'thequickbrownfox '
- >>> scytale_decipher('tqcrnxhukof eibwo ', 6)
- 'thequickbrownfox '
- >>> scytale_decipher('tqcrnx hukof eibwo ', 7)
- 'thequickbrownfox '
- """
- # transpositions = [i for i in range(math.ceil(len(message) / rows))]
- # return column_transposition_decipher(message, transpositions,
- # fillcolumnwise=False, emptycolumnwise=True)
- transpositions = [i for i in range(rows)]
- return column_transposition_decipher(message, transpositions,
- fillcolumnwise=True, emptycolumnwise=False)
-
-
-def railfence_encipher(message, height, fillvalue=''):
- """Railfence cipher.
- Works by splitting the text into sections, then reading across them to
- generate the rows in the cipher. The rows are then combined to form the
- ciphertext.
-
- Example: the plaintext "hellotherefriends", with a height of four, written
- out in the railfence as
- h h i
- etere*
- lorfns
- l e d
- (with the * showing the one character to finish the last section).
- Each 'section' is two columns, but unfolded. In the example, the first
- section is 'hellot'.
-
- >>> railfence_encipher('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 2, fillvalue='!')
- 'hlohraateerishsslnpeefetotsigaleccpeselteevsmhatetiiaogicotxfretnrifneihr!'
- >>> railfence_encipher('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 3, fillvalue='!')
- 'horaersslpeeosglcpselteevsmhatetiiaogicotxfretnrifneihr!!lhateihsnefttiaece!'
- >>> railfence_encipher('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 5, fillvalue='!')
- 'hresleogcseeemhetaocofrnrner!!lhateihsnefttiaece!!ltvsatiigitxetifih!!oarspeslp!'
- >>> railfence_encipher('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 10, fillvalue='!')
- 'hepisehagitnr!!lernesge!!lmtocerh!!otiletap!!tseaorii!!hassfolc!!evtitffe!!rahsetec!!eixn!'
- >>> railfence_encipher('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 3)
- 'horaersslpeeosglcpselteevsmhatetiiaogicotxfretnrifneihrlhateihsnefttiaece'
- >>> railfence_encipher('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 5)
- 'hresleogcseeemhetaocofrnrnerlhateihsnefttiaeceltvsatiigitxetifihoarspeslp'
- >>> railfence_encipher('hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers', 7)
- 'haspolsevsetgifrifrlatihnettaeelemtiocxernhorersleesgcptehaiaottneihesfic'
- """
- sections = chunks(message, (height - 1) * 2, fillvalue=fillvalue)
- n_sections = len(sections)
- # Add the top row
- rows = [cat([s[0] for s in sections])]
- # process the middle rows of the grid
- for r in range(1, height-1):
- rows += [cat([s[r:r+1] + s[height*2-r-2:height*2-r-1] for s in sections])]
- # process the bottom row
- 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.
- Works by reconstructing the grid used to generate the ciphertext, then
- unfolding the sections so the text can be concatenated together.
-
- Example: given the ciphertext 'hhieterelorfnsled' and a height of 4, first
- work out that the second row has a character missing, find the rows of the
- grid, then split the section into its two columns.
-
- 'hhieterelorfnsled' is split into
- h h i
- etere
- lorfns
- l e d
- (spaces added for clarity), which is stored in 'rows'. This is then split
- into 'down_rows' and 'up_rows':
-
- down_rows:
- hhi
- eee
- lrn
- led
-
- up_rows:
- tr
- ofs
-
- These are then zipped together (after the up_rows are reversed) to recover
- the plaintext.
-
- Most of the procedure is about finding the correct lengths for each row then
- splitting the ciphertext into those rows.
-
- >>> railfence_decipher('hlohraateerishsslnpeefetotsigaleccpeselteevsmhatetiiaogicotxfretnrifneihr!', 2).strip('!')
- 'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers'
- >>> railfence_decipher('horaersslpeeosglcpselteevsmhatetiiaogicotxfretnrifneihr!!lhateihsnefttiaece!', 3).strip('!')
- 'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers'
- >>> railfence_decipher('hresleogcseeemhetaocofrnrner!!lhateihsnefttiaece!!ltvsatiigitxetifih!!oarspeslp!', 5).strip('!')
- 'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers'
- >>> railfence_decipher('hepisehagitnr!!lernesge!!lmtocerh!!otiletap!!tseaorii!!hassfolc!!evtitffe!!rahsetec!!eixn!', 10).strip('!')
- 'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers'
- >>> railfence_decipher('horaersslpeeosglcpselteevsmhatetiiaogicotxfretnrifneihrlhateihsnefttiaece', 3)
- 'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers'
- >>> railfence_decipher('hresleogcseeemhetaocofrnrnerlhateihsnefttiaeceltvsatiigitxetifihoarspeslp', 5)
- 'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers'
- >>> railfence_decipher('haspolsevsetgifrifrlatihnettaeelemtiocxernhorersleesgcptehaiaottneihesfic', 7)
- 'hellothereavastmeheartiesthisisalongpieceoftextfortestingrailfenceciphers'
- """
- # find the number and size of the sections, including how many characters
- # are missing for a full grid
- n_sections = math.ceil(len(message) / ((height - 1) * 2))
- padding_to_add = n_sections * (height - 1) * 2 - len(message)
- # row_lengths are for the both up rows and down rows
- row_lengths = [n_sections] * (height - 1) * 2
- for i in range((height - 1) * 2 - 1, (height - 1) * 2 - (padding_to_add + 1), -1):
- row_lengths[i] -= 1
- # folded_rows are the combined row lengths in the middle of the railfence
- folded_row_lengths = [row_lengths[0]]
- for i in range(1, height-1):
- folded_row_lengths += [row_lengths[i] + row_lengths[-i]]
- folded_row_lengths += [row_lengths[height - 1]]
- # find the rows that form the railfence grid
- rows = []
- row_start = 0
- for i in folded_row_lengths:
- rows += [message[row_start:row_start + i]]
- row_start += i
- # split the rows into the 'down_rows' (those that form the first column of
- # a section) and the 'up_rows' (those that ofrm the second column of a
- # section).
- down_rows = [rows[0]]
- up_rows = []
- for i in range(1, height-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 cat(c for r in zip_longest(*(down_rows + up_rows), fillvalue='') for c in r)