python实现维尼吉亚密码

一 代码

1. #key='relations'
2. #plaintext='tomorrowiwillhaveagood'
4. key='helloworld'
5. plaintext=input('请输入明文：')
6. ascii='abcdefghijklmnopqrstuvwxyz'
7. keylen=len(key)
8. ptlen=len(plaintext)
9. ciphertext =''
10. i =0
11. while i < ptlen:
12. j = i % keylen
13. k = ascii.index(key[j])
14. m = ascii.index(plaintext[i])
15. ciphertext += ascii[(m+k)%26]
16. i +=1
18. print(ciphertext)
21. #维吉尼亚加密算法 解密
22. key='helloworld'
23. ciphertext=input('请输入密文：')
24. ascii='abcdefghijklmnopqrstuvwxyz'
25. keylen=len(key)
26. ctlen=len(ciphertext)
27. plaintext =''
28. i =0
29. while i < ctlen:
30. j = i % keylen
31. k = ascii.index(key[j])
32. m = ascii.index(ciphertext[i])
33. if m < k:
34. m +=26
35. plaintext += ascii[m-k]
36. i +=1
37. print(plaintext)

二 运行结果

请输入明文：tomorrowiwillhaveagood

asxzfncntzppwsorsrrrvh

请输入密文：asxzfncntzppwsorsrrrvh

tomorrowiwillhaveagood