I was going to say why is this news now? This was a big thing at the end of 2023. Like they even mentioend it in the article.

The practice first came to light in 2023 when Senator Ron Wyden sent a letter to the U.S. Department of Justice

I got news for you. Google does this too. Have a great day.

And the secure “lockdown” mode on iOS disables push notifications for exactly this reason. But the vast majority of people don’t use lockdown mode in their day to day, because it kills a lot of the functionality of the phone. Lockdown mode is intended for people who may actually be targeted by laser-focused hacking attempts. Politicians, celebrities, people with high security clearance, etc… It’s not something that the average person would use.

Apple even publishes this as a known vulnerability. It’s due to the way push notifications work. Similar to SMS, push notifications default to unencrypted because there isn’t a single unified system. Each carrier and cell manufacturer handles push notifications differently, so they’re kept unencrypted so that the public encryption key doesn’t get lost during transit; That would just result in scrambled junk messages.

A push notification, from a technical standpoint, is just a way to wake up an app. It doesn't have to contain any information.

So when you get a message, the messaging service sends a push notification through Apple/Google, which is a way of saying "Hey messaging app, wake up". The app then starts running in the background on your phone, connects to it's server, asks if there is anything new to know about, and the server tells it about a new message, if any. This can then generate a notification on your phone, but importantly what you are seeing in the notification did not come through Apple/Google, all that did was the "Hey messaging app, wake up!".

If authorities then request this data from Apple/Google, all they can see is the times at which your messaging app was asked to wake up. Not whether any message was actually received, or what it contained, or from who. Because all that never touched Apple/Google's systems, not even in an encrypted form.

That being said, some data can be sent directly through the Apple/Google system along with the wake up message, so it's not impossible that some apps include some metadata there. In theory they shouldn't. For example simple marketing notifications or ads often are just included with the push, because it's simple to do.

Signal is E2EE. While it does use notifications, there is no meaningful unencrypted content in them. The content of the notification you see is decrypted on-device.

Removed archive link, also paywalled.

:(

Articles Found:

1. https://m.slashdot.org/story/442846
2. https://arstechnica.com/tech-policy/2023/12/apple-admits-to-secretly-giving-governments-push-notification-data/
3. https://www.vice.com/en/article/apple-just-confirmed-governments-are-spying-on-peoples-phones-with-push-notifications/
4. https://www.imore.com/iphone/apple-admits-governments-can-spy-on-your-iphones-push-notifications-and-they-already-are
5. https://www.macrumors.com/2023/12/06/apple-governments-surveil-push-notifications/
6. https://appleinsider.com/articles/25/06/04/apple-approved-fewer-push-data-personal-info-demands-in-2024-despite-government-surge

Edit:

1. Removed archived link, paywalled, signin required
2. Added articles on topic

Yes, these are not "private" services, they are "secure messaging" services. Commonly confused issue. Privacy requires controlling the communication infrastructure. Security only requires controlling the items being shared.

Yes. 100%. Some app creators will encrypt the contents but I don't think they can encrypt the metadata.

Even the most "private" of companies like Signal and Proton don't provide any alternative either. Third-party fork Molly adds UnifiedPush support to Signal.

From Signal CEO:

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.)

https://mastodon.world/@Mer__edith/111563865413484025

Selfhosted gotify rules

Part of that is the responsibility of the app developer, since they define the payload that appears in the APNs push message. It’s possible for them to design it such that the push message really just says “time to ping your app server because something changed”. That minimizes the amount of data exposed to Apple, and therefore to law enforcement.

For instance the MDM protocol uses APNS. It tells the device that it’s time to reach out to the MDM server for new commands. The body of the message does not contain the commands.

That still necessarily reveals some metadata, like the fact that a message was sent to a device at a particular time. Often metadata is all that law enforcement wants for fishing expeditions. I think we should be pushing back on law enforcement’s use of broad requests (warrants?) for server data. We can and should minimize the data that servers have, but there’s limits. If servers can hold nothing, then we no longer have a functional Internet. Law enforcement shouldn’t feel entitled to all server data.

Thank you