libsecp256k1

Uses hand-tuned assembly for 32-bit ARM and efficient limb arithmetic (e.g., 5 52-bit limbs), making it one of the fastest secp256k1 implementations available.

Implements constant-time operations and runtime blinding to prevent timing and power analysis attacks, with a focus on being 'difficult to use insecurely.'

Self-contained with no heap allocation, making it suitable for embedded systems and reducing attack surface, as highlighted in the features list.

Includes optional modules for Bitcoin-specific protocols like Schnorr signatures (BIP-340) and MuSig2, ensuring compatibility with modern cryptographic standards.

Features extensive testing infrastructure and a structured design to facilitate review, aiming for high-assurance correctness and security.