There was a discussion here where change to SHA512 was suggested with only using the first 256 bits of the result. That way security would be increased while transaction sizes would not take more space.
that solves the problem of bigger length but raises the question of why stick to SHA-2 and not switch to SHA-3 while we are making that change.
With 64bit CPU:s SHA512 would actually be faster to calculate than SHA256. That is if the modern CPUs didn't have dedicated instruction sets for speeding up calculating SHA256, which they do.
how about using AVX512 for SHA512?
And I do not think we would have to change the elliptic curve if we just change the hash algorithm. We could, but they aren't really connected.
well hash functions are chosen based on the curve not the other way around so it doesn't make sense to me to use a 512 bit hash with a 256 bit curve which is why i say we may have to change to secp521r1 curve so that usage of a 512 bit hash makes sense.
although if the result is truncated (SHA512-256) then it could make some sense.
