CyberQ CTF 2025
11 challenges with 30 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 liveCryptography9
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.
Groundhog Day
5 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups, deriv-security/ctf-writeups, deriv-security/ctf-writeups, deriv-security/ctf-writeups
DSAstrous
4 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups, deriv-security/ctf-writeups, deriv-security/ctf-writeups
Gradient Descent into Secret Recovery
3 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups, deriv-security/ctf-writeups
Quotes
3 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups, deriv-security/ctf-writeups
ECDSA
2 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups
HashTag Broken
2 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups
Only a few bits are enough
2 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups
Oops I did it again
2 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups
Simple Oracle
2 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups
Uncategorised2
The upstream scoreboard did not say, so neither do we.
Backdoor Discovery
3 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups, deriv-security/ctf-writeups
Privacy Vulnerability Classifier
2 official solutionsAlso written up in: deriv-security/ctf-writeups, deriv-security/ctf-writeups