Very good post. I’m gonna go read everything else OP has written, now.

This is all varying degrees of okay, but:

1. The murica funding does not matter, and even making the server code public does not matter if the clients are open source, reliably updated, and have reproducible builds (all of which are true for Signal), at least when it comes to the content of your messages. End to end encryption means intermediaries like the network you send the encrypted content over, and third parties are taken out of the equation. Metadata is… more sticky because it involves a level of trust. It doesn’t really matter if the server code is open source since you can’t verify that it is running on the server your app interacts with. So you’re left with their privacy policy:

Additional technical information is stored on our servers, including randomly generated authentication tokens, keys, push tokens, and other material that is necessary to establish calls and transmit messages. Signal limits this additional technical information to the minimum required to operate the Services.

So the OP is correct that theoretically the metadata is still there, but literally all viable alternatives have the same problem.

2. The alternatives are different levels of bad:

• Matrix: The vast majority of Matrix users are on a single network controlled by Matrix.org, and default with Element, which is by a huge margin the most popular Matrix client. Matrix.org is registered in the UK, which isn’t exactly a privacy haven. Caveats:

  • You can self host Matrix, but the servers are ridiculously bloated and require very good (read expensive) hardware to sustain small or medium sized communities.
  • You still need to federate with Matrix.org unless you can get literally everyone you speak to to be on your own server, which also increases your liability and puts you at the mercy of your home country’s laws or those of wherever the VPS you are using is located.
  • If you federate with Matrix.org and other servers, a lot of metadata will leak as mentioned in the OP as well. Also matrix is slow and unreliable (messages are delivered late or can even go undelivered if there is a lot of traffic on the server.

• XMPP: XMPP is much less bloated than Matrix and much faster too. But it is a relic of the past. There are a billion different standards, no real subset of all available standards that everyone has agreed upon for a base, encryption is far from default and has to be enabled in individual clients and all servers they interact with, and most importantly, XMPP is also pretty damn unreliable. Simple things like image/media transfer tends to bork for no reason. It’s unpleasant to use it for anything other than text in my experience.

• Briar is cool but extremely, extremely limited as mentioned. At best it is good for burner conversations.

In conclusion, Signal is still the best messaging service of its kind. I’d be happy to tighten up my threat model by moving to something more viable and getting my contacts to do so too, but I’m yet to be convinced.

Also, this should go without saying, but please don’t fucking use Telegram.