def checkKeys(keyA, keyB, mode):
if keyA == 1 and mode == 'encrypt':
sys.exit('The affine cipher becomes weak when key A is set to 1. Choose different key')
if keyB == 0 and mode == 'encrypt':
sys.exit('The affine cipher becomes weak when key A is set to 1. Choose different key')
if keyA < 0 or keyB < 0 or keyB > len(SYMBOLS) - 1:
sys.exit('Key A must be greater than 0 and key B must be between 0 and %s.' % (len(SYMBOLS) - 1))
if cryptoMath.gcd(keyA, len(SYMBOLS)) != 1:
sys.exit('Key A %s and the symbol set size %s are not relatively prime. Choose a different key.' % (keyA, len(SYMBOLS)))
def checkKeys(keyA, keyB, mode):
if keyA == 1 and mode == 'encrypt':
sys.exit('The affine cipher becomes weak when key A is set to 1. Choose different key')
if keyB == 0 and mode == 'encrypt':
sys.exit('The affine cipher becomes weak when key A is set to 1. Choose different key')
if keyA < 0 or keyB < 0 or keyB > len(SYMBOLS) - 1:
sys.exit('Key A must be greater than 0 and key B must be between 0 and %s.' % (len(SYMBOLS) - 1))
if cryptoMath.gcd(keyA, len(SYMBOLS)) != 1:
sys.exit('Key A %s and the symbol set size %s are not relatively prime. Choose a different key.' % (keyA, len(SYMBOLS)))
def check_keys(keyA, keyB, mode):
if mode == "encrypt":
if keyA == 1:
sys.exit("The affine cipher becomes weak when key "
"A is set to 1. Choose different key")
if keyB == 0:
sys.exit("The affine cipher becomes weak when key "
"B is set to 0. Choose different key")
if keyA < 0 or keyB < 0 or keyB > len(SYMBOLS) - 1:
sys.exit("Key A must be greater than 0 and key B must "
f"be between 0 and {len(SYMBOLS) - 1}.")
if cryptomath.gcd(keyA, len(SYMBOLS)) != 1:
sys.exit(f"Key A {keyA} and the symbol set size {len(SYMBOLS)} "
"are not relatively prime. Choose a different key.")
def generateKey(keySize):
print('Generating prime p...')
p = rabinMiller.generateLargePrime(keySize)
print('Generating prime q...')
q = rabinMiller.generateLargePrime(keySize)
n = p * q
print('Generating e that is relatively prime to (p - 1) * (q - 1)...')
while True:
e = random.randrange(2 ** (keySize - 1), 2 ** (keySize))
if cryptoMath.gcd(e, (p - 1) * (q - 1)) == 1:
break
print('Calculating d that is mod inverse of e...')
d = cryptoMath.findModInverse(e, (p - 1) * (q - 1))
publicKey = (n, e)
privateKey = (n, d)
return (publicKey, privateKey)
def generateKey(keySize):
print('Generating prime p...')
p = rabinMiller.generateLargePrime(keySize)
print('Generating prime q...')
q = rabinMiller.generateLargePrime(keySize)
n = p * q
print('Generating e that is relatively prime to (p - 1) * (q - 1)...')
while True:
e = random.randrange(2 ** (keySize - 1), 2 ** (keySize))
if cryptoMath.gcd(e, (p - 1) * (q - 1)) == 1:
break
print('Calculating d that is mod inverse of e...')
d = cryptoMath.findModInverse(e, (p - 1) * (q - 1))
publicKey = (n, e)
privateKey = (n, d)
return (publicKey, privateKey)
def hackAffine(message):
print('Hacking...\n[Press CTRL + C or CTRL + D to quit at any time]')
for key in range(len(affineCipher.SYMBOLS) ** 2):
keyA = affineCipher.getKeyParts(key)[0]
if cryptoMath.gcd(keyA, len(affineCipher.SYMBOLS)) != 1:
continue
decryptedText = affineCipher.decryptMessage(key, message)
if not SILENT_MODE:
print('Key #%s: %s...' % (key, decryptedText[:40]))
if detectEnglish.isEnglish(decryptedText):
print('\nPossible encryption hack:')
print('Key #%s: %s...' % (key, decryptedText[:40]))
print("Enter 'D' for done, or just press 'Enter' to continue hacking:")
response = input('> ')
if response.strip().upper().startswith('D'):
return decryptedText
return None
# Affine Key Test
# Source: http://inventwithpython.com/hacking (BSD Licensed)
# Modified by: Harshil Darji (github.com/H-Darji)
# This program proves that the keyspace of the affine cipher is limited to len(SYMBOLS) ^ 2.
import affine_cipher as affineCipher, cryptomath_module as cryptoMath
message = 'Make things as simple as possible, but not simpler.'
print('Message: %s\nEncryption using key,' % message)
for keyA in range(2, 100):
key = keyA * len(affineCipher.SYMBOLS) + 1
if cryptoMath.gcd(keyA, len(affineCipher.SYMBOLS)) == 1:
print('%s | %s' % (keyA, affineCipher.encryptMessage(key, message)))
def getRandomKey():
while True:
keyA = random.randint(2, len(SYMBOLS))
keyB = random.randint(2, len(SYMBOLS))
if cryptoMath.gcd(keyA, len(SYMBOLS)) == 1:
return keyA * len(SYMBOLS) + keyB
def getRandomKey():
while True:
keyA = random.randint(2, len(SYMBOLS))
keyB = random.randint(2, len(SYMBOLS))
if cryptoMath.gcd(keyA, len(SYMBOLS)) == 1:
return keyA * len(SYMBOLS) + keyB
