HellGates, custom CPU gate-level challenge

Posts Hello, HellGates September 19, 2026 · 26 min Introduction # In the Summer of 2025 I published a crackme called HellGates. Then I published it in November crackmes.one .

Basically I designed a custom 32-bit CPU encrypted & bit addressable (not byte addressable) in VHDL, synthesized it down to a gate-level netlist with multiple layers of obfuscation, anti-tamper, timing checks & anti-debug. It was designed for humans, but apparently worked well against LLMs too, until now.

Not the humans, they spent weeks/months on it and gave up. Not the LLMs, Claude failed, ChatGPT failed, and DeepSeek failed after days or weeks of work guided by hints I gave to people, ending with the model declaring the challenge "computationally infeasible with available resources."

Then, in September 2026, GPT-6 solved it in under 20-30 minutes on SRE-Bench .

Thank you Zhuo Zhang for making this possible !