Взлом Vigenere cipher

Скрипты

python

 1 def encryption(plaintext, keyword):
 2     txt_len = len(plaintext)
 3     keyword *= txt_len // len(keyword) + 1
 4     keyword = keyword[:txt_len]
 5     encoded = ""
 6     for c in range(txt_len):
 7         newchar = ord(plaintext[c]) + ord(keyword[c]) - 194
 8         newchar %= 25
 9         encoded += chr(newchar + 97)  # 97 = ord('a')
10     return encoded