我正在尝试使用 mod 37 在 Python 中编写 Vigenere Cipher 程序。我需要帮助找出问题所在。
alphabet= "abcdefghijklmnopqrstuvwxyz0123456789 "
def Let2Ind(x):
return(ord(x)-ord("a"))
def Ind2Let(n):
return(alphabet[n])
def encVigenere(key, plaintext):
ciphertext=""
L=len(key)
for i in range(len(plaintext)):
A=Let2Ind(key[i%L])
B=Let2Ind(plaintext[i])
C=(A+B)%37
D=Ind2Let(C)
ciphertext= ciphertext+D
return(ciphertext)
def decVigenere(key, ciphertext):
plaintext=""
L=len(key)
for i in range(len(ciphertext)):
E=Let2Ind(key[i%L])
F=Let2Ind(ciphertext[i])
G=(F-E)%37
H=Ind2Let(G)
plaintext= plaintext+H
return(plaintext)