Ambrose Andrews @znalo@librem.one

I know it will take time, but the Fediverse developers should strongly consider making the following opinionated technical decisions:

Use RFC 9421 instead of the earlier HTTP Signature spec.
Make Ed25519 the default algorithm, not 2048-bit RSA.

Ed25519 has a lot of advantages over RSA and ECDSA.

Over 2048-bit RSA:

Shorter signatures
Shorter keys (both secret and public), less storage/bandwidth overhead
More security (112-bit vs 126-bit)

Over ECDSA:

It's much faster than ECDSA
You don't have to worry about biased nonces leaking your secret key through lattice reduction
Tuned for security (no weird parameters)

Over both RSA and ECDSA:

EdDSA is constructed to provide Exclusive Ownership, which is a stronger notion of security
Easier to implement in constant-time

Bonus:

Ed25519 is approved for use in FedRAMP systems (FIPS 186-5), which Common Criteria sometimes cares about.

See more here: https://ianix.com/pub/ed25519-deployment.html and https://www.keylength.com/en/4/