凯撒加密解密Python代码

凯撒加密Python实现

import string

key = int(input("输入凯撒密钥(1-25之间的数):"))
intab = string.ascii_lowercase + string.ascii_uppercase
outtab1 = string.ascii_lowercase[key:] + string.ascii_lowercase[:key]
outtab2 = string.ascii_uppercase[key:] + string.ascii_uppercase[:key]
outtab = outtab1 + outtab2
trantab = str.maketrans(intab, outtab)
plaintext = input("输入明文:")
ciphertext = plaintext.translate(trantab)
print("密文为：" + ciphertext)

凯撒解密Python实现

import string

key = int(input("输入凯撒密钥(1-25之间的数):"))
intab = string.ascii_lowercase + string.ascii_uppercase
outtab1 = string.ascii_lowercase[key:] + string.ascii_lowercase[:key]
outtab2 = string.ascii_uppercase[key:] + string.ascii_uppercase[:key]
outtab = outtab1 + outtab2
trantab = str.maketrans(outtab, intab)
ciphertext = input("输入密文:")
plaintext = ciphertext.translate(trantab)
print("明文为：" + plaintext)

凯撒加密函数和解密函数实现

import string

def CaesarEncrypt(key, plaintext):
    key = abs(key) % 26
    intab = string.ascii_lowercase + string.ascii_uppercase
    outtab1 = string.ascii_lowercase[key:] + string.ascii_lowercase[:key]
    outtab2 = string.ascii_uppercase[key:] + string.ascii_uppercase[:key]
    outtab = outtab1 + outtab2
    trantab = str.maketrans(intab, outtab)
    ciphertext = plaintext.translate(trantab)
    return ciphertext

def CaesarDecrypt(key, ciphertext):
    key = abs(key) % 26
    intab = string.ascii_lowercase + string.ascii_uppercase
    outtab1 = string.ascii_lowercase[key:] + string.ascii_lowercase[:key]
    outtab2 = string.ascii_uppercase[key:] + string.ascii_uppercase[:key]
    outtab = outtab1 + outtab2
    trantab = str.maketrans(outtab, intab)
    plaintext = ciphertext.translate(trantab)
    return plaintext

def main():
    ciphertext = CaesarEncrypt(3, 'I love you.')
    print(ciphertext)
    plaintext = CaesarDecrypt(3, ciphertext)
    print(plaintext)

if __name__ == '__main__':
    main()