1. import random
2. import math as floor
3.  
4.  
5. def genKys(length, choice):
6.     key = [0] * length
7.     for i in range(choice):
8.         key[floor.floor(random.random() * (length - 1))] = 1
9.     return key
10.  
11. def enc(plain, key):
12.     length = len(key)
13.     cipher = [None] * length
14.     for i in range(length):
15.         cipher[i] = 1 if key[i] == plain[i] else 0
16.     return cipher
17.  
18. def getBts(plain):
19.     length = len(plain)
20.     bits = [None] * length * 8
21.     for i in range(length):
22.         for j in range(8):
23.             bits[8 * i + 7 - j] = (int)(ord(plain[i]) / pow(2, j)) % 2
24.     return bits
25.  
26. def main():
27.     txt = input("Enter cipher text : ")
28.     length = len(txt)
29.     key = genKys(length * 8, floor.floor(random.random() * length * 8))
30.     plain = getBts(txt)
31.     print("plaintext : ")
32.     print(plain)
33.     cipher = enc(plain, key)
34.     print("ciphertext : ")
35.     print(cipher)
36.     deciphered = enc(cipher, key)
37.     print("deciphered : ")
38.     print(deciphered)
39.  
40. if __name__ == "__main__":
41.     main()