Solving for faster SHA-1 collision detection
Summary
The post introduces sha1dc, a Rust-based rewrite of SHA-1 with collision detection, using a code generator to fit collision tests into SIMD lanes. It explains the two-stage prefix-tail design, the role of a solver in optimizing vector groups, and benchmarks showing substantial speedups over the existing sha1-checked approach, with real-world gains in git pack verification. The discussion ties the work to disturbance-vector theory from cryptographic research and compares it to hardware-accelerated SHA-1 paths.