i already did it anyhow, i needed a neat little interface that makes it easy to dial back to the btcec signatures but also neat enough to use as a MAC for the noise protocol implementation i started working on (mainly for a secure shell)

it uses the bitcoin-core/secp256k1 library directly and can be used either for signing/verification or verification only, with minimal overhead, it's more than 2x faster at verifying and about 5x faster at signing, so it definitely has utility as an MAC, as it was i already had determined i could use it to snip packets into 1.5kb chunks each with a distinct signing key for 8Mb/s, so, being this was the big overhead it's probably gonna be more like 20Mb/s especially if the SIMD sha256 based CTR encryption is also 2x or better, the signatures are the biggest overhead