matrix
though you will need lotsa RAM for federation if you use synapse (mine keeps bogging down now after a year of mild use (could also be a bug idk, it allocates all the RAM and then nothing goes), now im waiting for the new server software dendrite to be able to migrate from synapse... allthough i wouldnt lose much if i just nuked the synapse instance)
Yes, and I have in the past. But that does not solve the issue completely. If the police asks me some information about one of my contacts, I'll have some metadata stored in my homeserver, and I'll need to hand it over. And vice versa.
It's better that the server does not have access to this information at all in the first place.
Most important is who when with who which both leak to the server operators
https://signal.org/blog/looking-back-as-the-world-moves-forw...
(edit: answering to your initial message, that said that Signal operators also have access to the same metadata, but I guess my comment still answers your sentence "Most important is who when with who which both leak to the server operators" - Signal operators have showed they can't provide this information)
But Signal could store that data because they have access to that dats
Can I do this easily and still have my homeserver work correctly with Matrix?
Anyway, the law would probably require any operator to keep this data for a while since they have access to it. And I can't rely on my contact's homeservers to delete this data even if they can (technically and legally).
They have access to that data alone through the fact that they are in control of their servers and, thus, can see who sends and receives messages.
Even on a theoretical level their sealed sender technique doesn't work: https://www.ndss-symposium.org/ndss-paper/improving-signals-...
Now, include lower level technical Details such as the IP layer.
1. Imagine you connect to a server to send a message. Now, you send a message to someone else. The server can't see who you are, right? Because the letter misses your name. Imagine someone else sends a message to you.
2. Imagine you to connect to the same server to receive messages that the server stored for delivery with your name on it. The server gives you the messages.
Do you notice something?
The information can be obtained in an automated way.
I suppose the moderators would still be at risk of hosting platforms and ISPs dropping their homeserver.
EDIT: if the person you're talking to is hosted on Google, Google has all the metadata. Even if one person is hosted on Google and is part of a room you're in, Google has all the metadata in that room.
In 2022 e2ee is the standard for messages but not metadata, and unfortunately Matrix doesn't tackle it, so no, you can't expect 100% privacy.
Would be interesting to know if Amazon could reconstruct that information without Signals knowledge
Matrix does leak more meta data though, e.g. message relationships for instance, but what does that matter?