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.
Technical paper describing a hardware architecture for accelerating arbitrary-precision integer arithmetic using a 2D spacetime matrix design to overcome Von Neumann bottlenecks in modular arithmetic operations at 10 GHz clock speeds.
Claude Fable 5.1 solved a 370-year-old cipher in forty-four minutes, demonstrating AI capability in search-heavy cryptanalytic tasks. The achievement is presented as evidence of how modern AI excels at problems requiring extensive searching and testing.