如何编写Ceaser密码Python

时间:2019-07-07 21:27:16

标签: python encryption caesar-cipher

我不确定如何开始编写程序。

input = input("Input the text you would like encrypted")


def cipher_text(letter_code):
    for i in input:
        number_code = ord(i) + 3
        letter_code = chr(number_code)
        print(letter_code)

def plain_text(letter_code,regular_text):
    for i in input:
        regular_text = letter_code - 3
        print(regular_text)
print("Encrypted text")
cipher_text()
print("Unencrypted text")
plain_text()

很抱歉,我不确定如何开始。另外,请提供建议而不是答案。

1 个答案:

答案 0 :(得分:0)

从数学上讲,如果我们在encryption中看到了Caesar cipher技术,则获得加密字母的公式为:

c = (x+n) mod 26, 

其中c是加密字母的位置值,x是实际字母的位置值,n是移位。 同样,对于decrypt每个字母,我们使用下面给出的公式:

c = (x-n) mod 26

您可以使用下面的代码来了解如何实现Caesar Cipher

def encrypt(plain_text, s):
    encrypted_text = ''
    for i in range(len(plain_text)):
        if plain_text[i] == ' ':
            encrypted_text = encrypted_text + plain_text[i]
        elif plain_text[i].isupper():
            encrypted_text = encrypted_text + chr((ord(plain_text[i])+s-65)%26+65)
        else:
            encrypted_text = encrypted_text + chr((ord(plain_text[i])+s-97)%26+97)
    return encrypted_text


def decrypt(encrypt_text, s):
    decrypted_text = ''
    for i in range(len(encrypt_text)):
        if encrypt_text[i] == ' ':
            decrypted_text = decrypted_text + encrypt_text[i]
        elif encrypt_text[i].isupper():
            decrypted_text = decrypted_text + chr((ord(encrypt_text[i])-s-65)%26+65)
        else:
            decrypted_text = decrypted_text + chr((ord(encrypt_text[i])-s-97)%26+97)
    return decrypted_text



plain_text = input("Input the text you would like encrypted:")
s = int(input("Enter shift:"))
encrypt_text = encrypt(plain_text, s)
print("Encrypted text: {}".format(encrypt_text))
print("Decrypted text: {}".format(decrypt(encrypt_text, s)))

样本输出:

Input the text you would like encrypted:Taj Mahal

Enter shift:3
Encrypted text: Wdm Pdkdo
Decrypted text: Taj Mahal