Question

在本章中，您可以了解替换密码的简单实现，它根据简单替换密码技术中使用的逻辑显示加密和解密的消息。 这可以被视为编码的替代方法。

Code

您可以使用以下代码使用简单替换密码执行解密 -

import random
chars = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ' + \
   'abcdefghijklmnopqrstuvwxyz' + \
   '0123456789' + \
   ':.;,?!@#$%&()+=-*/_<> []{}`~^"\'\\'
def generate_key():
   """Generate an key for our cipher"""
   shuffled = sorted(chars, key=lambda k: random.random())
   return dict(zip(chars, shuffled))
def encrypt(key, plaintext):
   """Encrypt the string and return the ciphertext"""
   return ''.join(key[l] for l in plaintext)
def decrypt(key, ciphertext):
   """Decrypt the string and return the plaintext"""
   flipped = {v: k for k, v in key.items()}
   return ''.join(flipped[l] for l in ciphertext)
def show_result(plaintext):
   """Generate a resulting cipher with elements shown"""
   key = generate_key()
   encrypted = encrypt(key, plaintext)
   decrypted = decrypt(key, encrypted)
   print 'Key: %s' % key
	print 'Plaintext: %s' % plaintext
   print 'Encrypted: %s' % encrypted
   print 'Decrypted: %s' % decrypted
show_result('Hello World. This is demo of substitution cipher')

输出 (Output)

上面的代码为您提供了如下所示的输出 -