维吉尼亚密码的加密解密

维吉尼亚密码的加密解密

# -*- coding:utf-8 -*-

def weijiniya_jiemi(ciphertext,key):
    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

def weijiniya_jiami(plaintext,key):
    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

def main():
    print 'CHOICE:'
    print '1:weijiniya_jiami'
    print '2:weijiniya_jiemi'
    choice = input()
    if choice == 1:
        plaintext = input('jiama_string1:')
        key = input('key:')
        weijiniya_jiami(plaintext,key)
    elif choice == 2:
        ciphertext = input('jiemi_string1:')
        key = input('key:')
        weijiniya_jiemi(ciphertext,key)
    else:
        print('error！')
        main()

if __name__ == '__main__':
    main()

好像cmd窗口有点问题，中文一直显示不出来，就直接用拼音了哈哈哈。。。

再加一个凯撒的，虽然直接有网址可以解：

# -*- coding:utf-8 -*-
def change(c,i):
    c = c.lower()
    num =ord(c)
    ifnum >=97andnum <=122:
        num =97+ ((num -97) + i) %26
    returnchr(num)

def kaisa_jiami(string,i):
    string_new =''
    forsinstring:
        string_new += change(s,i)
    print(string_new)
    return string_new

def kaisa_jiemi(string):
    for i in range(25):
        print('\n', i,'\n')
        i +=1
    kaisa_jiami(string,i)

def main():
    print('请选择需要的操作：')
    print('1：凯撒加密')
    print('2：凯撒解密')
    choice =input()
    if choice ==1:
        string =input('请输入需要加密的字符串：')
        num =int(input('请输入需要偏移的位数：'))
        kaisa_jiami(string,num)
    else if choice ==2:
        string =input('请输入需要解密的字符串：')
        kaisa_jiemi(string)

    else:
        print('输入错误，请重试！')
        main()
if__name__ =='__main__':
    main()