March 2025 monthly summary for risc0/risc0 focusing on business value and technical accomplishments. Delivered a cross-language API for bigint2 cryptographic primitives by exposing Rust functions with C extern "C" linkage for modular arithmetic operations across 256-bit and 384-bit fields, enabling interoperability and external system usage. The work is anchored by a single, traceable commit implementing the feature (ZKVM-1227) and prepared for broader adoption.

February 2025 highlights: Implemented and integrated 384-bit arithmetic capabilities across Zirgen and RISC0, enabling large-number cryptographic operations in both the circuit/library and ZKVM contexts. Key additions include 384-bit modular arithmetic (addition, subtraction, multiplication, inversion) in bigint2 for Zirgen (circuit and library) with build-system exposure, and analogous 384-bit support in RISC0’s bigint2 and ZKVM extended field arithmetic, including new methods, binary blobs, and updated tests. Delivered an end-to-end BLS12-381 pairing example in ZKVM with host/guest code, Cargo configurations, and README, plus documentation updates for precompiles. Strengthened test coverage and binary artifacts to validate larger-number cryptographic workflows. Overall, these efforts advance cryptographic capability, scalability, and production readiness for larger-number cryptographic protocols.

November 2024 (risc0/zirgen): Delivered a major Keccak circuit refactor and optimization focused on maintainability and efficiency. Key changes include register aliasing, unified constraints, introduction of new components, and refined memory argument handling to reduce data columns and XOR operations, along with code formatting improvements and moving definitions from SHA256 to Keccak. Commits: 238fb9d93f3646d6f11bf326b2eaf63d0624c0c1 (ZIR-226) and 8adb1a9f90446e2096b9e820c134bd04c8e1f199 (ZIR-244). No major bugs fixed this month; emphasis was on architectural enhancement and code quality. Impact: cleaner, faster cryptographic circuit code with improved maintainability and scalability for future work and easier verification. Technologies/skills: cryptographic circuit design, Keccak optimization, register aliasing, unified constraints, memory argument handling, code quality and formatting, Rust/ZK-circuit tooling.