libsecp256k1 The canonical C library for secp256k1. Maintained by Bitcoin Core team; constant-time, optimized. Repo: . Build Modules - Default: ECDSA. - — x-only pubkeys (BIP340). - — Schnorr signatures (BIP340). - — recoverable ECDSA. - — ECDH. - — MuSig2 (BIP327). - — FROST (experimental). - — internal testing. API C API: Properties - Constant-time everywhere. - Endomorphism-optimized scalar mult. - Bindings: rust, python, JS (wasm), Go, JVM, etc. Use cases - Bitcoin Core's signing engine. - All language bindings build on this. - Performance-critical apps. Common pitfalls - to avoid leaks.…