Constantine is a high-performance modular cryptography library implemented in Nim, with bindings for C, Rust, and Go. It provides production-grade implementations of elliptic curve arithmetic, pairings, BLS signatures, KZG polynomial commitments, and Ethereum-specific protocols (EIP-2537, EIP-4844, EIP-7594). The library is designed with constant-time operations to resist side-channel attacks, includes a custom lock-free work-stealing threadpool for parallel execution, and features hand-optimized assembly for x86 (ADX, BMI2) and ARM64. It also contains experimental GPU code generation (CUDA, AMD ROCm) via LLVM IR. The codebase is extensively tested against GMP, OpenSSL, and official Ethereum test vectors, and includes formal verification of field arithmetic via fiat-crypto. Despite its research components (Sage scripts, optimization papers), the dominant character is a reusable, production-oriented library for blockchain and zero-knowledge proof systems.
Blitzar is a high-performance C++ library for GPU-accelerated cryptographic zero-knowledge proofs, developed by Space and Time. It provides multi-scalar multiplication (MSM), Pedersen commitments, inner product arguments, sumcheck proofs, and sequential commitments over multiple elliptic curves (Curve25519/Ristretto255, BLS12-381, BN254, Grumpkin). The library supports both CPU and CUDA GPU backends, with a stable C API and Rust bindings (blitzar-sys). It is designed for use in Space and Time's Proof of SQL, enabling analytic queries on large datasets with sub-second proof generation. The codebase is well-structured with extensive unit tests, benchmarks, and a Bazel/Nix build system. It incorporates optimized algorithms (Pippenger, bucket methods) and low-level field/curve arithmetic adopted from libsodium and zkcrypto, demonstrating strong engineering craftsmanship in GPU cryptography.
This repository is a pure Python library implementing elliptic curve cryptography algorithms, specifically ECDSA (Elliptic Curve Digital Signature Algorithm), ECDH (Elliptic Curve Diffie-Hellman), and EdDSA (Edwards-curve Digital Signature Algorithm). It provides key generation, signing, verification, and shared secret derivation functionalities across multiple curve types including NIST prime curves, Brainpool curves, and twisted Edwards curves (Ed25519/Ed448). The library is structured as a modular package with clear separation of concerns: high-level API in `keys.py`, low-level arithmetic in `ellipticcurve.py`, curve definitions in `curves.py`, ASN.1 DER handling in `der.py`, and utility functions for encoding/decoding in `util.py`. While the code is well-structured and includes comprehensive test suites, the project explicitly states it is not designed for production security due to vulnerability to side-channel attacks, recommending wrappers like `pyca/cryptography` for sensitive applications.