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 all 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.
Yes. Would love to see this compared to XMPP, maybe Signal.
It matters a lot! Hete’s one dramatic example:
Some may find this acceptable, considering the army is rightfully targetting terrorists. However the same techniques are used by autoritarian states to target opposants, journalists, human right defenders…
Even if there’s a technical reason, it shows the protocol or implementations lack good metadata protections. Hopefully the matrix foundation can fix this soon. If not, people should look for more secure options.
It depends on your threat profile. I’m fine with that data being public on matrix - which I use for communities.
The less data is known, the better
These aren’t mutually exclusive trade-offs: Matrix could support communities while minimizing or encrypting metadata by default. There should be a protocol that doesn’t require device details and profile data to be exposed just to participate.
Yes, it’s good that there is a solution to the problem