RSA.py

# coding:utf-8
import random
import Prime


# encryption ,according to the formula:m^e = c (mod n) , calculate c ,c == secret,m == message
def encryption(message, puk):
 return Prime.quick_pow_mod(message, puk[1], puk[0])


# decryption ,according to the formula:c^d = m (mod n), calculate m ,
def decryption(secret, prk):
 return Prime.quick_pow_mod(secret, prk[1], prk[0])


def get_RSAKey():
 RSAKey = {}
 prime_arr = Prime.get_rand_prime_arr(2)
 p = prime_arr[0]
 q = prime_arr[1]
 while p == q:
 q = random.choice(prime_arr)
 n = p * q
 s = (p - 1) * (q - 1)
 e = 65537
 d = Prime.mod_inverse(e, s)
 print("p = ", p, ",q = ", q)
 print("n = ", n)
 print("e = ", e, ",d = ", d)
 puk = [n, e]
 prk = [n, d]
 RSAKey['puk'] = puk
 RSAKey['prk'] = prk
 return RSAKey


if __name__ == '__main__':
 RSAKey = get_RSAKey()
 print("Enter a number less and shorter than ", len(str(RSAKey['puk'][0])), ",", RSAKey['puk'][0], ":")
 # only encrypt a number type
 message = int(input())
 secret = encryption(message, RSAKey['puk'])
 print("After the encryption data :", secret)
 print(len(str(secret)))
 message = decryption(secret, RSAKey['prk'])
 print("After the decryption data :", message)
 print(len(str(message)))