There's nothing wrong with Signal's centralization model in a worrying sense. It acts only as a clueless message relay, and it has near-zero information on any of its users, even as it delivers messages from person to person. The only information Signal knows is if a phone number is registered and the last time it connected to the server. There is great care taken to make sure everything else is completely end-to-end encrypted and unknowable, even by subpoena.

The only real issue with Signal's centralization is that if Signal the company goes down, then all clients can no longer work until someone stands up a new server to act as a relay again. Signal isn't the endgame of privacy, but it's the best we have right now for a lot of usecases, and it's the only one I've had any luck converting normies to as it's very polished and has a lot of features. IMO, by the time the central Signal server turns into an actual problem we'll hopefully have excellent options available to migrate to.

Also TMK, the only reason you still need a phone number for Signal is to combat spam. You can disable your phone number being shown to anyone else in the app and only use temporary invite codes to connect with people, so I don't count the phone number as a huge problem, though the requirement does still annoy me as it makes having multiple accounts more difficult and asserts a certain level of privilege.

I totally agree with you. But!

But Signal from what I've heard really wants us to use their server.

Signal doesn't have their own servers. Instead, they rent servers from 4 companies, 3 of them is Google, Amazon, and Microsoft. So Signal is relying on Big Tech and if Big Tech decides that enough is enough, they can easily shut Signal down.

THAT is what I find most terrifying. And why not use their own server? Not enough money, but they are working on it (good).

And to make it a little bit worst: Signal depends on a third party company for sending out SMS. Your phone number is therefore handled by not Signal, but by yet another company, highly likey an American company. And they are against privacy invading companies at the same time they are one. Oh, the irony.

You want sources? Sure.

• https://signal.org/legal/ (below "Information we may share")
• https://signal.org/blog/signal-is-expensive/

Don't get me wrong, I absolutely love the idea of Signal. But there is flaws that makes Signal more privacy invading than privacy friendly.

Because it's nearly impossible to convince friends and family to use anything other than iMessage or "the text app" on their phone. The process you've described is basically akin to swimming the English Channel for the general public. I'd do it. But expecting anyone else to is just a pipe dream.

I'm already a social outcast and second class citizen for not using imessage. Asking my friends and family to install a whole separate app just to communicate with me puts me firmly in weirdo territory.

Many people will tell you you have to sacrifice your principles because interface, because "normies" (which is an elitist way of telling you that non-elitist people are idiots....), etc. I say: stick to your dreams!

Against XMPP+OMEMO

If I could get a single person to use Signal instead of Whatsapp... or even the nerds I know to use matrix instead of Discord...

First of all, thank you for your recommendation. I was on the fence between Siskin IM and Monal, so I went with Monal to replace AstraChat.

I’ve used Signal before and it was fine but I prefer not to give a phone number to open an account; there are other services that don’t require it.

Speaking of services, I use Simple X, Session, Matrix and Delta Chat (occasionally). Most of my eccentric mix of family, friends and colleagues are happy to try something new or switch as long as it doesn’t require a phone number to sign up. They’re slowly leaving Signal, WhatsApp, Telegram and limiting access to their iMessage.

In my experience, Session syncs very well between my devices which makes it my favorite. I chose FluffyChat over Element because of the App Privacy in iOS.

I’ve used XMPP since shortly after it was developed. I still use it today.

HOWEVER, while the clients are relatively good, as long as they support the extensions you want to use, I’ve found maintaining the server to be a royal headache. Between protocol and extension improvements, security updates and general server instability, I find that it’s a constant struggle to have it running and compatible with whatever client someone is using, when someone actually uses it.

Signal, on the other hand, pretty much always works, has a single client, and nobody has to worry about managing the server except Signal. So as infrastructure, it makes a lot more sense.