This is incorrect. They also have your full name and address by extension

I didn't suggest otherwise. This was about whether they can correlate that to additional information. I am already assuming that the US government might try to maliciously compromise the servers, without needing the pretense of national security laws.

I'm not an expert in cryptography or Signals codebase, but my understanding is that the client app uses separate connections to verify the session (something that can be tied to your phone number on a compromised server) and to send a message out. The initial contact discovery process can leak info if you are searching for specific phone numbers, and this could be mitigated by using the QR code or usernames to get an ID directly. The actual pre key fetch is sent as a separate request not tied to your session verification. So outside of timing attacks, it shouldn't let Signal know who I am talking to day to day even if they know that I have connected to the person at one point.

I think it's cool that Simplex and Matrix allow selhosting, and especially Simplex's 2 hop technique. That should make it much more difficult for someone trying to map things out. However if the average person is going to be using the default servers, I don't see how a compromised server is any less of a problem than with Signal's ones.

I recommend Signal to non-technical users trying to get away from Facebook/Instagram/whatsapp. I might start recommending Simplex too if it gets popular enough and goes through a similar level of scrutiny that Signal had. I'm already comfortable using a variety of chat platforms / self hosting for myself.

The lack of a phone number requirement does limit the extent of social graph mapping. I hope signal will do away with that requirement as they've promised to for some time. The risk though is spam, which is already a problem now that signal is getting popular.

Just read the first article I posted, it gets into all this.

I did look over it again, and I still find the CIA section to be silly. I'll refer back to these old comments from myself and someone else:

https://lemmy.ca/comment/5401873

https://lemmy.ca/post/16397504/7661724

The 2nd article is the signal CEO Meredith Whitaker interviewing with lawfare, which is a US defense industry think-tank.

Again, I would say this is a big leap. The CEO agreeing to an interview with a think tank that has ties to the defense industry is not the same thing as Signal having ties to the defense industry. She has done many interviews talking about Signal, with a variety of orgs of different ownership and politics