def test_encrypt(self):
"""Tests encrypt function for Vigenere cipher"""
self.assertEqual(
Vigenere.encrypt('A' * 26, ALPHABET), ALPHABET)
self.assertEqual(
Vigenere.encrypt('A' * 26, ALPHABET[:13]), ALPHABET[:13] * 2)
self.assertEqual(
Vigenere.encrypt(ALPHABET, ALPHABET), ALPHABET[::2] * 2)
with self.assertRaises(Vigenere.VigenereError):
Vigenere.encrypt(5, ALPHABET)
with self.assertRaises(Vigenere.VigenereError):
Vigenere.encrypt(ALPHABET, range(5))
def encrypt(text, key):
"""Encrypts text using the One-Time Pad cipher
E(x) = Vigenere.encrypt(text, key)
text : string
key : string
"""
if type(text) is not str:
raise OneTimePadError('Can only encrypt strings.')
if type(key) is not str:
raise OneTimePadError('key must be a string.')
if len(key) < len(text):
raise OneTimePadError('key must be at least the same length as text.')
return Vigenere.encrypt(utils.fix_text(text), utils.fix_text(key))
def __encrypt(message, key):
# Split message in half
Ln = message[:len(message) / 2]
Rn = message[len(message) / 2:]
# Get keys
Rail_Fence_key = Jordan_Harman_Algorithm_1.get_rail_key(key)
Caesar_key = Jordan_Harman_Algorithm_1.get_caesar_key(key)
Vigenere_key = Jordan_Harman_Algorithm_1.get_vigenere_key(key)
# Begin Rounds
for x in range(0, 8):
Rn = Vigenere.encrypt(Rn, Vigenere_key)
Rn = Rail_Fence.encrypt(Rn, Rail_Fence_key)
Rn = Caesar.encrypt(Rn, Caesar_key)
Ln, Rn = Rn, Ln
return Ln + Rn
def validate_guess(keylens, fileids, alphabet, num_candidates):
keys = list(keylens.keys())
#for each fileid, we will want to check whether the correct guess is made
#for all keys
found = 0
not_found = 0
indecipherable = 0
for fileid in fileids:
#print("PLAINTEXT: ", fileid)
#setting plaintext
plaintext = corpus.gutenberg.raw(fileid)
plaintext = plaintext[0:300]
for key in keys:
ciphertext, ciphertext_file = vg.encrypt(key, plaintext)
#getting most likely key lengths
cipher_match_indices, cipher_matches = vg.find_matches(ciphertext)
most_likely_lengths, sorted_factor_counts = vg.likely_key_lengths(
ciphertext)
if type(sorted_factor_counts) == int:
indecipherable += 1
continue
most_likely_lengths = sorted_factor_counts[:num_candidates]
#print("Included: ", keylens.get(key) in most_likely_lengths, "|Key length: ", keylens.get(key), "|Choices: ", most_likely_lengths)
if keylens.get(key) != 1:
if keylens.get(key) in most_likely_lengths:
#print("Included: ", True, "|Key length: ", keylens.get(key), "|Choices: ", most_likely_lengths)
found += 1
else:
print("Included: ", False, "|Key length: ", keylens.get(key), "|Choices: ",\
most_likely_lengths, "|Next: ", sorted_factor_counts[:num_candidates+1])
not_found += 1
percent_top5 = (found) / (found + not_found)
percent_indecipherable = (indecipherable) / (found + not_found +
indecipherable)
return percent_top5, percent_indecipherable
def choose_cipher(cipher_name, key, option, input_file, output_file):
#Playfair
if cipher_name == "PLF":
if option == "ENC":
pass
elif option == "DEC":
pass
else:
print("Invalid option! Options are ENC/DEC")
#Row Transposition
elif cipher_name == "RTS":
rowtransposition = RowTransposition()
rowtransposition.setKey(key)
if option == "ENC":
plain_text = read_file(input_file)
cipher_text = rowtransposition.encrypt(plain_text)
write_file(output_file, cipher_text)
elif option == "DEC":
cipher_text = read_file(input_file)
plain_text = rowtransposition.decrypt(cipher_text)
write_file(output_file, plain_text)
else:
print("Invalid option! Options are ENC/DEC")
#Railfence
elif cipher_name == "RFC":
railfence = Railfence()
railfence.setKey(key)
if option == "ENC":
plain_text = read_file(input_file)
cipher_text = railfence.encrypt(plain_text)
write_file(output_file, cipher_text)
elif option == "DEC":
cipher_text = read_file(input_file)
plain_text = railfence.decrypt(cipher_text)
write_file(output_file, plain_text)
else:
print("Invalid option! Options are ENC/DEC")
#Vigenere
elif cipher_name == "VIG":
vigenere = Vigenere()
vigenere.setKey(key)
if option == "ENC":
plain_text = read_file(input_file)
cipher_text = vigenere.encrypt(plain_text)
write_file(output_file, cipher_text)
elif option == "DEC":
cipher_text = read_file(input_file)
plain_text = vigenere.decrypt(cipher_text)
write_file(output_file, plain_text)
else:
print("Invalid option! Options are ENC/DEC")
#Caesar
elif cipher_name == "CES":
caesar = Caesar()
caesar.setKey(int(key))
if option == "ENC":
plain_text = read_file(input_file)
cipher_text = caesar.encrypt(plain_text)
write_file(output_file, cipher_text)
elif option == "DEC":
cipher_text = read_file(input_file)
plain_text = caesar.decrypt(cipher_text)
write_file(output_file, plain_text)
else:
print("Invalid option! Options are ENC/DEC")
else:
print("Invalid cipher name chosen!")
