Matrix team drafted a useful spec in the last few months:
This was followed up by two scrutinizing but ultimately positive blog posts by a community member:
Unfortunately they apparently rn out of funding for this work, so it’s stalled at the moment. I believe the work was happening as a substrate of their overarching effort to become MLS compatible.
The MIMI/MLS standardization effort is well worth reading up on for anyone working on nomadic identity in the fediverse. There’s a lot of overlapping requirements pertaining to identity.
End-to-end (E2E) security is a critical property for modern user
communications systems. E2E security protects users’ communications
from tampering or inspection by intermediaries that are involved in
delivering those communcations from one logical endpoint to another.
In addition to the much-discussed E2E encryption systems, true E2E
security requires an identity mechanism that prevents the
communications provider from impersonating participants in a session,
as a way to gain access to the session. This document describes a
high-level architecture for E2E identity, identifying the critical
mechanisms that need to be specified.
See also: