Not in ActivityPub no.

The main privacy/security issue is mostly mitigated by the fact that there's a sync behavior for accounts and follows and distribution of content where the host can push revocation messages, triggering other servers to delete follows and wipe cached account data originating from that hosting server, which means that somebody who takes over a domain after a wipe can't imitate the exact same accounts. But old links can still be redirected because there's no way to verify what they were supposed to point to, so some degree of impersonation remains possible unless other servers agree to preemptively defederate...