IceCTF 2016 – Substituted

Stage 1: Substituted

Author: 5k33tz

Description: We got a substitute flag, I hear they are pretty lax on the rules… crypted.txt

Clicking on the link brings us to the substituted flag, with much other text:

I’d like to give a shout out to my co-worker (you know who you are) for making an amazing find: http://quipqiup.com/index.php

quipqiup is a cryptogram solver that allows the input for “clues” or seed type values.

Here is the list of clues that we’ve deduced from the puzzle. These we likely guesses, that turned out to be correct:

Lw! = Hi!
Gyzvecy ke WvyVKT! = Welcome to IceCTF!
The former clue is confirmed at the bottom, where we can see a string that is taking shape of a flag – WvyVKT{jzgjrd_zwdkym_ke_reso_dsbdkwksky_tzjqd}

This will allow us to enter the clues to let the solver do its magic:

The top hit gives us something that is in English, and what appears to be a flag:

Flag = IceCTF{always_listen_to_your_substitute_flags}

Comments

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