Keep It Simple: Leverage W3C Credentials Working Group and Credentials Community Group, and others as well.

[bobwyman]

"As a user of ActivityPub, I would benefit if AS/AP relied on technologies and methods that have become, or are becoming, standards within other areas that are likely to be of interest to me. I don't want to have to learn to use or deploy software which is specific to AS/AP unless the capability provided is truly unique to AS/AP or is not addressed by other commonly accepted standards."

E2EE may require software or practices which are very similar to those that have long been the subject of development within the W3C's Credentials Working Group or Credentials Community Group. Ideally, AS/AP would not "re-invent the wheel" if the Credentials* groups, or others, have already developed a solution that could be reasonably adopted.

[nightpool]

While I support this as a general principle, I think the way this is phrased as a user story is a little misleading, and a perversion of the Priority Of Constituencies. I think it would be more honestly written as a developer-user-story or spec-editor-user-story. Whether the use of a specific standard does or doesn't avoid "reinventing the wheel" is only relevant to a user in so far as actual interoperability is present, which the adoption of an existing solution may in fact hinder, if that solution is overly complicated or does not use technology already in wide deployment by major implementors

[bumblefudge]

I would say that maybe Verifiable Credentials address specific use-cases, but are built up from building blocks like Data Integrity signatures that could be really useful here... so I kind of agree with nightpool that maybe developer user stories would be more useful at this stage, although i'm happy to represent #teamVerifiability at every stage 💪