I know it will take time, but the Fediverse developers should strongly consider making the following opinionated technical decisions:<li>Use RFC 9421 instead of the earlier HTTP Signature spec.</li><li>Make Ed25519 the default algorithm, not 2048-bit RSA.</li>
Ed25519 has a lot of advantages over RSA and ECDSA.
Over 2048-bit RSA:<li>Shorter signatures</li><li>Shorter keys (both secret and public), less storage/bandwidth overhead</li><li>More security (112-bit vs 126-bit)</li>
Over ECDSA:<li>It's much faster than ECDSA</li><li>You don't have to worry about biased nonces leaking your secret key through lattice reduction</li><li>Tuned for security (no weird parameters)</li>
Over **both RSA and ECDSA**:<li>EdDSA is constructed to provide Exclusive Ownership, which is a stronger notion of security</li><li>Easier to implement in constant-time</li>
Bonus:<li>Ed25519 is approved for use in FedRAMP systems (FIPS 186-5), which Common Criteria sometimes cares about.</li>
See more here: and
Things that use Ed25519
Things that use the Ed25519 signature system
Keylength - NIST Report on Cryptographic Key Length and Cryptoperiod (2020)
Cryptographic key length recommendations and cryptoperiods extract from NIST Special Publication 800-57 Part 1, Recommendation for Key Management.
