Jane Street created a reverse-engineering challenge involving a physical chip layout (GDS file) rather than executable code. The solver must recover the circuit's logic by analyzing polygons, nets, and gates to determine what input the ASIC accepts as correct, following a path from physical layout through gate behavior to constraints.
A custom 32-bit CPU encrypted at gate-level with anti-tamper and anti-debug protections went unsolved for a year by humans and multiple LLMs, until GPT-6 solved it in 20-30 minutes using side-channel cryptanalysis to exploit weak encryption protecting the CPU state. The challenge featured a virtual architecture with 16 general-purpose registers, bit-addressable memory, and obfuscated VHDL synthesis.