Matrix Metadata Problem: the server sees everything except your messages

People pick Matrix because of end-to-end encryption. But E2EE only protects message content — everything around it is plaintext.

The server sees:

  • Your ID, IP, client type and version, device you use
  • Your presence, typing status, read receipts
  • Which rooms you join and when you join/leave
  • Who else is in those rooms → your entire social graph
  • Room names, topics, avatars (all plaintext state)
  • For every message: who sent it, which room, a millisecond timestamp, type, size

And federation copies most of that to every other server whose users are in the room. Your “social footprint” isn’t one copy — it’s as many as there are servers.

  • stratself@lemdro.idEnglish
    0·
    2 months ago

    Kindly find me proof that the Matrix protocol explicitly sends a user client’s version and device details towards another server when engaging in federation.

    Do note that Matrix and open protocols are federated, and requires some amount metadata to actually process+route stuff.