Changelog

• 0.5.3 (2026-01-10)

  • Bumps the ppad-sha256 and ppad-hmac-drbg dependencies.

• 0.5.2 (2025-12-28)

  • Adds an explicit 64-bit architecture constraint.
  • Tests on GHC.10.3.

• 0.5.1 (2025-12-27)

  • Improves the constant-time semantics in wNAF scalar multiplication, replacing "indexing via a constant-time selected value" by performing a full window scan and selecting via mask.

• 0.5.0 (2025-12-21)

  • We get a significant upgrade to all functionality by pulling in the ppad-fixed library for large unsigned and Montgomery-form integers. Constant-time and allocation properties are made much more rigorous across the board, as we no longer depend on 'Integer' whatsoever.

    This version also improves performance radically throughout. A summary of the speedups achieved:

    sign_schnorr: ~7.1x speedup verify_schnorr: ~4.5x speedup sign_ecdsa: ~1.5x speedup verify_ecdsa: ~4.5x speedup

• 0.4.0 (2025-06-21)

  • Scalar multiplication, signing, verifying, and ECHD functions are now all total, returning 'Nothing' when supplied with invalid inputs.
  • Adds a group element check to 'mul_wnaf'.

• 0.3.0 (2025-03-14)

  • Adds 'ecdh' for computing ECDH secrets, any given secret being the SHA256 hash of the x-coordinate of the appropriate secp256k1 point.

• 0.2.2 (2025-02-16)

  • Exports the secp256k1 "point at infinity" as _CURVE_ZERO.

• 0.2.1 (2024-12-18)

  • Adds 'serialize_point' for compressed-format serialization of secp256k1 points.

• 0.2.0 (2024-11-08)

  • Adds wNAF ("w-ary non-adjacent form") scalar multiplication, as well as fast 'sign' and 'verify' variants for Schnorr and ECDSA (disambiguated by a trailing apostrophe) that make use of it.

    Each wNAF-powered function requires a 'Context' consisting of precomputed secp256k1 generator multiples; one can be gotten via 'precompute'.

    Note that the non-wNAF-powered sign and verify functions have incurred a slight performance decrease (on the order of tens to hundreds of microseconds) as a result.

  • Adds 'parse_sig' for parsing compact signatures.

  • Adds a dependency on the 'primitive' library (already transitively required via 'ppad-hmac-drbg').

• 0.1.0 (2024-10-19)

  • Initial release, supporting public key derivation and Schnorr & ECDSA signatures on secp256k1.