1 min readCTF · Write-up · DEF CON Group
DCG Coimbatore CTF 2026: 12th of 230+, solo, no LLMs
Playing solo under a no-LLM rule at DEF CON Group 91422, what the hard challenges exposed, and the full write-up of 21 challenges.
DCG91422's CTF at Kumaraguru College of Technology had a no-LLM policy, and I think that was the right call. I played solo under the Flaggers United name and finished 12th among 230+ teams.
What the hard challenges taught me
The easy and medium challenges were fun. The hard ones exposed my gaps: pwn and crypto need much stronger programming fundamentals when there's no AI to lean on. More gaps found than wins — which is exactly what I needed.
The write-up
I documented every challenge I solved, 21 across 8 categories:
- Beginner (4): Hidden, Caesars Emporium, H3h3, Agent of Chaos
- Crypto (2): Enjoy your meal, Artifact
- Reverse engineering (4): BASIC, Ghost, kitty_cat, BabyDenuvo
- Forensics (4): DNS Tunnel, BetweenTheFrames, Memory Shadows, Deleted Evidence
- Web (2): Magical Gallery, Hidden Schema
- Misc (2): Romeo and Juliet, Git Necromancy
- OSINT (2): Training Wheels, Absolute Cine
- Pwn (1): babypwn
Day 2: the conference
The standout talk was on building n-days with multiple AI agents, a pipeline that fetches CVEs from NVD, reads the code, extracts routes, builds an exploit and validates it, with a feedback loop between the steps. Very practical.