ASIS CTF 2026
Challenge archive & solutions — cryptography and reverse engineering.
This repository is a public ASIS CTF 2026 challenge archive containing captured challenge material, optimized solution code, and rewritten technical documentation. Each challenge has a dedicated write-up covering protocol details, cryptanalysis, attack steps, mathematical derivations, and implementation caveats.
Challenges
Fence
NTRU-like negacyclic lattice attack combined with an XOR-accreted stream cipher.
Headache
Numerical system identification of a 60-parameter nonlinear oracle.
Mario
GF(16) oil-and-vinegar multivariate quadratic key recovery from leaked report vectors.
Pancake
AES partial-collision search causing GCM keystream reuse.
Sultan
Flask web challenge with bounded modular transcripts and lattice recovery.
linchan
GF(2) matrix-code similarity with planted rank-25 structures and conjugator recovery.
Less Is More
Merkle openings, noisy subset equations, and projective-key recovery.
Notes
- Solutions, analysis, and documentation in this archive were optimized and rewritten with AI assistance.
- The documentation is a study reference and is not a substitute for the original challenge infrastructure.
- Read the repository README for per-challenge details and caveats.