NSSCTF_crypto_[CISCN 2023 初赛]Sign_in_passwd
提示:base家族 古典密码
题目:
j2rXjx8yjd=YRZWyTIuwRdbyQdbqR3R9iZmsScutj2iqj3/tidj1jd=D
GHI3KLMNJOPQRSTUb%3DcdefghijklmnopWXYZ%2F12%2B406789VaqrstuvwxyzABCDEF5
首先拿到这题目直接去随波逐流跑一边发现解不出来就要想不是简单的base64了
直接上脚本
import base64
import string
from Crypto.Util.number import *
str1 = "j2rXjx8yjd=YRZWyTIuwRdbyQdbqR3R9iZmsScutj2iqj3/tidj1jd=D"
new = "GHI3KLMNJOPQRSTUb=cdefghijklmnopWXYZ/12+406789VaqrstuvwxyzABCDEF"
inti = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
print (base64.b64decode(str1.translate(str.maketrans(new,inti))))
运行后flag为
flag{8e4b2888-6148-4003-b725-3ff0d93a6ee4}
修改一下
NSSCTF{8e4b2888-6148-4003-b725-3ff0d93a6ee4}