They ask the push providers (Apple/Google) for data on the push token from e.g. a messaging app. This way they associate the account from an app with an identity.

Very overlooked point. You can find privacy guides online but very few even suggest that FCM etc. might have privacy issues, let alone explain exactly why. It seems this has already been used by law enforcement in the past: https://www.wired.com/story/apple-google-push-notification-surveillance/

The Molly-FOSS fork of Signal (which aims to be even more secure/private) actually supports self-hosted push notifications using UnifiedPush.

I also found this comment:

As far as I know, FCM on Android can be configured to use a notification payload (which is piped through Google's servers). But for a release app this is discouraged, especially if you are privacy conscious. An app would normally use FCM to receive a trigger and look up the received message from the app's own backend. See here for more information.

good points altough the number is note saved. the hash of the phonenumber is hashed so Signal could not hand out your number, just the hash.

This is exactly my take. It basically holds for Signal too.

The question of self-censorship is too often overlooked IMO. The knowledge that nobody is reading your messages except their intended recipients is empowering and liberating. No one is filling a database with information about you and your friends, because they can't. You can say exactly what you would say at the dinner table and not think twice about it.

In a police state with mass surveillance (we all know the big examples) you don't have this privilege. Whether or not you think about it consciously, you are constantly monitoring and policing what you say - and therefore ultimately, to some extent, what you think.

I've been in a couple of those places recently. I can tell you that just the banal act of using Signal there (sometimes over VPN) felt almost exhilarating, like jumping the prison walls.

In historical terms, free speech is a vanishing rare thing. It absolutely is not the norm and it bothers me that so many people in the West don't seem to know this. We should not take it for granted.

The problem I have with Signal is that it itself pushes people onto the "shitty operating systems". It does not allow registering from desktop, at least officially. There are workarounds, but they're cumbersome (especially for a non-technical person, whom Signal is supposed to appeal to), and the official client outright tells you go to use a phone first. And even then, apparently the desktop client is not even full-featured, and not the priority.

I know there are degoogled OSes (running Graphene myself), but you'd need to get lucky or choose a phone with this in mind, while a random given laptop is likely to be able to run Linux.

They funded encryption too. Why don't you stop using that?

Be paranoid in your estimation of how much privacy you have, but diligent in your efforts to get more of it for everyone.

Will people read this and stop using the internet or stop caring about privacy?

Cynicism is a self-fulfilling prophesy. If everything's bad then there's no reason to care, and if nobody cares then everything will be bad.

For things to get better, or not get worse, cynics depend on others to care about those things. To me that feels terribly like freeloading.

indeed they are ☞ President of @signalapp : https://mastodon.world/@Mer__edith/111563865413484025

PSA: We've received questions about push notifications. First: push notifications for Signal NEVER contain sensitive unencrypted data & do not reveal the contents of any Signal messages or calls–not to Apple, not to Google, not to anyone but you & the people you're talking to.

In Signal, push notifications simply act as a ping that tells the app to wake up. They don't reveal who sent the message or who is calling (not to Apple, Google, or anyone). Notifications are processed entirely on your device. This is different from many other apps.

What's the background here? Currently, in order to enable push notifications on the dominant mobile operating systems (iOS and Android) those building and maintaining apps like Signal need to use services offered by Apple and Google.

Apple simply doesn’t let you do it another way. And Google, well you could (and we've tried), but the cost to battery life is devastating for performance, rendering this a false option if you want to build a usable, practical, dependable app for people all over the world.*

So, while we do not love Big Tech choke points and the control that a handful of companies wield over the tech ecosystem, we do everything we can to ensure that in spite of this dynamic, if you use Signal your privacy is preserved.

*(Note, if you are among the small number of people that run alt Android-based operating systems that don't include Google libraries, we implement the battery-destroying push option, and hope you have ways to navigate.)

There are several open protocols that meet your criteria that aren’t Matrix (with most of them using double-ratchet encryption similar to if not exactly like Signal). Due to server costs (Matrix eats a lot of RAM & storage), medium-sized entities usually bow out so the Matrix network largely consist of a few 1–10 user servers & massive centralization around Matrix.org & the hosted servers they provide. Since almost all the messages get synced to the Matrix.org server if just one Matrix.org user is in your room or whatever, all metadata will be synced to the mothership in Matrix.org that was originally funded by Israeli intelligence.

the Matrix stack. BUT! It’s hard to set up and nobody uses it!

Is it really that hard? For me it was just downloading an app and creating an account--easier than setting up Facebook Messenger. I think it doesn't yet have the network that Messenger/Signal/Whatsapp have, which makes it harder to use with others, but setting up has been easy in my experience.