Cryptography - HW1.5 (Challenge-05)

def encrypt_xor(plain_text, key):
    result = ''
    # iterate each char of word
    for i in range(len(plain_text)):
        # key to xor on
        xor = ord(key[i % len(key)])
        # char to xor
        char = ord(plain_text[i])
        # xor resutl
        res = char ^ xor
        # convert to hex
        res_hex = "{0:0{1}x}".format(res, 2)
        # append result
        result += res_hex
    return result


if __name__ == "__main__":
    # input key
    key = input()
    # input plain text
    plain_text = input()

    # encryption
    cipher = encrypt_xor(plain_text, key)

    # result
    print(cipher)