@tedu As a first step, we can start accepting Ed25519 keys in addition to RSA keys. As far as I know, publicKey field can't be an array, and even if it can, many projects will fail to process an array there.

There's another proposal that describes a way out this situation: https://codeberg.org/fediverse/fep/src/branch/main/fep/521a/fep-521a.md

With a new property that can contain any kind of public key, implementations can start adding Ed25519 keys to actors. Once a sufficient portion of Fediverse supports EdDSA, projects can start using it for outgoing requests and activities