Reverse Engineering

An in-depth reverse engineering analysis of Claude Code’s API request signing mechanism, revealing how the cch hash and xxHash64 are implemented, the secrets of Bun’s runtime, and how Anthropic protects API calls with native code.

Jane Street released a special ML puzzle: given the complete neural network weights, find an input that makes it output non-zero. This isn’t a typical black-box attack - it requires truly understanding what the network is computing. A college student spent days, going from linear programming to SAT solvers, and finally discovered the network was hiding an MD5 hash function.