Cryptography With Python 简明教程

Cryptography with Python - XOR Process

在本章节中，让我们了解 XOR 过程及其在 Python 中的编码。

In this chapter, let us understand the XOR process along with its coding in Python.

Algorithm

加密和解密的 XOR 算法将明文转换为 ASCII 字节格式，并使用 XOR 过程将其转换为指定的字节。它为用户提供以下优势：-

XOR algorithm of encryption and decryption converts the plain text in the format ASCII bytes and uses XOR procedure to convert it to a specified byte. It offers the following advantages to its users −

  1. Fast computation

  2. No difference marked in left and right side

  3. Easy to understand and analyze

Code

可以使用以下代码段执行 XOR 过程：-

You can use the following piece of code to perform XOR process −

def xor_crypt_string(data, key = 'awesomepassword', encode = False, decode = False):
   from itertools import izip, cycle
   import base64

   if decode:
      data = base64.decodestring(data)
   xored = ''.join(chr(ord(x) ^ ord(y)) for (x,y) in izip(data, cycle(key)))

   if encode:
      return base64.encodestring(xored).strip()
   return xored
secret_data = "XOR procedure"

print("The cipher text is")
print xor_crypt_string(secret_data, encode = True)
print("The plain text fetched")
print xor_crypt_string(xor_crypt_string(secret_data, encode = True), decode = True)

Output

XOR 过程的代码给你以下输出：-

The code for XOR process gives you the following output −

xor

Explanation

  1. The function xor_crypt_string() includes a parameter to specify mode of encode and decode and also the string value.

  2. The basic functions are taken with base64 modules which follows the XOR procedure/ operation to encrypt or decrypt the plain text/ cipher text.

Note − XOR 加密用于加密数据，并且很难通过暴力攻击方法（这是一种通过生成随机加密密钥来匹配正确的密码文本）破解。

Note − XOR encryption is used to encrypt data and is hard to crack by brute-force method, that is by generating random encrypting keys to match with the correct cipher text.