It's not a technical limitation, just a design decision. Everyone on Signal's network is known by their phone numbers. You cannot pick a username, as such. The phone number is the username.

I really don't get the point of that.

I mean, sure one can get more-or-less anonymous phone numbers. But why create the need for that?

There are things like keys for verification :)

> I really don't get the point of that

To prevent spam and promote discovery. Finding someone on WhatsApp or Signal is easier than on WeChat as with the latter someone might be using a screen name, or an email address or a phone number.

Discovery and preventing spam should not take precedence over privacy for an app that supposedly has privacy as its number one priority.

Privacy isn't signal's one priority.

Good enough privacy for the masses is.

They are always making these tradeoffs, and always make the same decisions. Perfect privacy in every situation isn't the goal. The goal is better privacy than the average person currently has, while still maintaining a level of convenience that the average user well accept.

That's what google and Facebook say.

Indeed. So one must conclude that privacy isn't the top priority.

Why is it is easier to find someone when you can only use one identifier to find them, instead of several? Note that WeChat also uses phone numbers to limit spam, so you can find anyone if you know their number. (But exchanging QR codes is the preferred method of sharing contact information, to the point where I couldn't call most of my contacts except through WeChat.)

> To prevent spam

I suspected that, but have they openly said it? I suspect it's also to deter criminal activity.

Wow that's an amazingly stupid and short sighted decision. Why would they tie their app to a legacy numbering system which doesn't even serve to accurately identify people?

So that they do not have to worry about that. It's a pretty smart decision to offload the issue of unique IDs to an existing infrastructure.

I really do not like it either too though.

... Same reason WhatsApp got so many users and became worth billions? It's simple, straightforward, and just works for most people.

Your messages still go through OWS servers. I believe signal routes messages via phone #.

Signal client is open source though, so maybe this is easy to work around.

OWS has specifically said they won't accept federation...

I was more suggesting a separate centralized service that doesn't use phone #s, but true that you still wouldn't be able to use it with standard Signal users.