If you are writing #ActivityPub stuff, and interacting with existing implementations, you'll need to figure out http request signing - used for signing/verifying fetches.This document is a great survey of the current landscape, and an excellent place t...

John Spurlock

If you are writing #ActivityPub stuff, and interacting with existing implementations, you'll need to figure out http request signing - used for signing/verifying fetches.

This document is a great survey of the current landscape, and an excellent place to start for implementers:

ActivityPub and HTTP Signatures
https://swicg.github.io/activitypub-http-signature/