zcashd/doc/release-notes.md

(note: this is a temporary file, to be added-to by anybody, and moved to release-notes at release time)

Notable changes

Signature validation using libsecp256k1

ECDSA signatures inside Zcash transactions now use validation using https://github.com/bitcoin/secp256k1 instead of OpenSSL.

Depending on the platform, this means a significant speedup for raw signature validation speed. The advantage is largest on x86_64, where validation is over five times faster. In practice, this translates to a raw reindexing and new block validation times that are less than half of what it was before.

Libsecp256k1 has undergone very extensive testing and validation upstream.

A side effect of this change is that libconsensus no longer depends on OpenSSL.