def vigenere(cipher="citxwjcsybhnjvml", key="vector"):
plaintext = ""
for i, char in enumerate(cipher):
shift = toNum(key[i % len(key)])
d = toNum(char)
plaintext += toLetter((d-shift) % 26)
return plaintext
def vigenere(plaintext="hereishowitworks", key="vector"):
plaintext.lower()
cipher = ""
for i, char in enumerate(plaintext):
shift = toNum(key[i % len(key)])
d = toNum(char)
cipher += toLetter((d + shift) % 26)
return cipher
def shift(plaintext="test", key=3):
plaintext = plaintext.lower()
cipher = ""
for char in plaintext:
d = toNum(char)
cipher += toLetter((d + key) % 26)
return cipher
def affine(cipher="cvvwpm", alpha=9, beta=2):
inverse = mInverse(alpha,26)
plaintext = ""
for char in cipher:
d = toNum(char)
plaintext += toLetter((inverse*d - inverse*beta)%26)
return plaintext
def affine(plaintext="affine", alpha=9, beta=2):
if gcd(alpha, 26) != 1:
raise Exception
plaintext = plaintext.lower()
cipher = ""
for char in plaintext:
d = toNum(char)
cipher += toLetter((alpha * d + beta) % 26)
return cipher
def hill(cipher="poh", key="GYBNQKURP", block_size = 3):
cipher = cipher.lower()
key = key.lower()
keyMatrix = buildMatrix(key,block_size)
from numpy.linalg import inv
keyMatrix = inv(keyMatrix).tolist()
numbers=[]
for letter in cipher:
numbers.append(toNum(letter))
numbers = [numbers[i:i+block_size] for i in range(0, len(numbers),block_size)]
for plain_block in range(len(numbers)):
vTranspose = [[item] for item in numbers[plain_block]]
numbers[plain_block] = matrixMultiply(keyMatrix,vTranspose)
cipher = [num for sublist in numbers for liste in sublist for num in liste]
return cipher
def hill(plaintext="CAT", key="GYBNQKURP", block_size=3):
if len(key) % block_size != 0:
raise Exception("Matrix Size error")
plaintext = plaintext.lower()
key = key.lower()
keyMatrix = buildMatrix(key, block_size)
numbers = []
for letter in plaintext:
numbers.append(toNum(letter))
numbers = [
numbers[i:i + block_size] for i in range(0, len(numbers), block_size)
]
for plain_block in range(len(numbers)):
vTranspose = [[item] for item in numbers[plain_block]]
numbers[plain_block] = matrixMultiply(keyMatrix, vTranspose)
cipher = [
toLetter(num % 26) for sublist in numbers for liste in sublist
for num in liste
]
return "".join(cipher)
def shift(cipher="whvw", key=3):
plaintext = ""
for char in cipher:
d = toNum(char)
plaintext+= toLetter((d-key)%26)
return plaintext
