IDEH CTF 2026
12 challenges with 17 published solutions between them. The writeups for this event were found in public repositories. Each link is pinned to the commit it was read from.
Where these writeups liveReverse engineering5
Work out what a compiled program does without its source, then work backwards from the check to the input that passes it.
Blue Horizon
2 official solutionsAlso written up in: KH0BZ4/IDEH-CTF-2026, KH0BZ4/IDEH-CTF-2026
Exfil
2 official solutionsAlso written up in: KH0BZ4/IDEH-CTF-2026, KH0BZ4/IDEH-CTF-2026
Neural Validator
2 official solutionsAlso written up in: KH0BZ4/IDEH-CTF-2026, KH0BZ4/IDEH-CTF-2026
Easy rev
1 official solutionAlso written up in: KH0BZ4/IDEH-CTF-2026
Frozen Truth
1 official solutionAlso written up in: KH0BZ4/IDEH-CTF-2026
Uncategorised4
The upstream scoreboard did not say, so neither do we.
Cipher
1 official solutionAlso written up in: KH0BZ4/IDEH-CTF-2026
Important doc
1 official solutionAlso written up in: KH0BZ4/IDEH-CTF-2026
Last S
1 official solutionAlso written up in: KH0BZ4/IDEH-CTF-2026
PRINTER VOICE
1 official solutionAlso written up in: KH0BZ4/IDEH-CTF-2026
Cryptography2
Recover a plaintext or a key from something that was supposed to protect it. In practice: identify the scheme, find the parameter the author got wrong, exploit it.
Emotional Encryption
2 official solutionsAlso written up in: KH0BZ4/IDEH-CTF-2026, KH0BZ4/IDEH-CTF-2026
XORCEPTIOn
2 official solutionsAlso written up in: KH0BZ4/IDEH-CTF-2026, KH0BZ4/IDEH-CTF-2026
Misc1
Everything that fits no other box: esolangs, puzzles, scripting exercises, and the jail escapes that have not yet earned their own category.
Logic Burst
1 official solutionAlso written up in: KH0BZ4/IDEH-CTF-2026