Faster Signatures on secp256k1

In my last post I mentioned that both the Schnorr and ECDSA signature schemes on secp256k1 could be made faster via the so-called wNAF method for elliptic curve point multiplication (short for the cumbersome “w-ary non-adjacent form”). I implemented wNAF for ppad-secp256k1 afterwards, adding a bunch of functions that use it internally. The only “downside” to the use of wNAF is that one needs to…