本文实例讲述了Python实现的维尼吉亚密码算法。分享给大家供大家参考,具体如下:

一 代码
# -*- coding:utf-8 -*-
#key='relations'
#plaintext='tomorrowiwillhaveagood'
print("创新互联测试结果:")
key='helloworld'
plaintext=raw_input('请输入明文:')
ascii='abcdefghijklmnopqrstuvwxyz'
keylen=len(key)
ptlen=len(plaintext)
ciphertext =''
i =0
while i < ptlen:
j = i % keylen
k = ascii.index(key[j])
m = ascii.index(plaintext[i])
ciphertext += ascii[(m+k)%26]
i +=1
print(ciphertext)
#维吉尼亚加密算法 解密
key='helloworld'
ciphertext=raw_input('请输入密文:')
ascii='abcdefghijklmnopqrstuvwxyz'
keylen=len(key)
ctlen=len(ciphertext)
plaintext =''
i =0
while i < ctlen:
j = i % keylen
k = ascii.index(key[j])
m = ascii.index(ciphertext[i])
if m < k:
m +=26
plaintext += ascii[m-k]
i +=1
print(plaintext)