1.开局一张图片
2.用binwalk、stegsolve等没有发现异常。在kali用LSB-cloacked-pixel-master工具有内容
python2 lsb.py extract attachment.png 001.txt lovekfc
3.查看txt文本,得到密文
PVSF{vVckHejqBOVX9C1c13GFfkHJrjIQeMwf}
4.根据提示将keyword放到前面,从26个英文字母里把 “lovekfc”提出来放到前面制作密钥
lovekfcabdghijmnpqrstuwxyz
5.后根据密钥替换密文中的字母解密,使用python跑出此处Nihilist加密
# -*- coding:utf-8 -*-
import string
ciphertext = 'PVSF{vVckHejqBOVX9C1c13GFfkHJrjIQeMwf}'
secretkey = 'lovekfcabdghijmnpqrstuwxyz'
plaintext = ''
for letter in ciphertext:
if letter in string.ascii_lowercase:
index = secretkey.lower().index(letter)
plaintext += string.ascii_lowercase[index]
continue
if letter in string.ascii_uppercase:
index = secretkey.upper().index(letter)
plaintext += string.ascii_uppercase[index]
continue
plaintext += letter
print(plaintext)
6.得到flag