this post was submitted on 07 Apr 2026
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TLDR: signal content in Apple notification can be retrieved even after signal app deletion.

I saw from this reddit thread: Signal messages retrieved from iPhone after uninstalling app. : signal

Referencing this news article: Pretti Killing May Affect ICE Prairieland "Antifa Cell" Terrorism Trial

The mention of signal is in court documents here: March 10: Federal Trial Day 12 - Support the Prairieland Defendants

Signal chat evidence from Sharp’s device (Exhibit 158):
Messages were recovered from Sharp’s phone through Apple’s internal notification storage — Signal had been removed, but incoming notifications were preserved in internal memory. Only incoming messages were captured (no outgoing).

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[–] anon_8675309@lemmy.world 3 points 1 hour ago (1 children)

That’s my biggest issue with notifications. Notifications should just notify you that something happened and you need to open the app to find out. Carrying actual data ON the notification is a no-no.

But what do I know, I’m an old developer not one of these modern vibe kiddies.

[–] baggachipz@sh.itjust.works 3 points 1 hour ago

A notification doesn’t have to carry any data in its payload; Signal devs could take care of that.

[–] TheFrirish@tarte.nuage-libre.fr 2 points 4 hours ago

Honestly I have a much much much MUCH MUCH bigger issue with the fact that it is an American and Centralised service.

FBI still can't access it though.

[–] ZoteTheMighty@lemmy.zip 37 points 11 hours ago (1 children)

But Apple told me in an ad that they're better for privacy?!?

[–] Chais@sh.itjust.works -2 points 7 hours ago* (last edited 7 hours ago) (1 children)

And you believed that?? Do you also believe Micro$lop when they tell you that Windows is the best OS?

[–] Quill7513@slrpnk.net 8 points 1 hour ago

here on lemmy we interpret obvious sarcasm as sincerity

[–] SnoringEarthworm@sh.itjust.works 71 points 14 hours ago* (last edited 14 hours ago) (5 children)

Basically, they didn't do this:

(I'm on Android, so I don't know what the options look like in iOS, but they should be identical.)

[–] Crackhappy@lemmy.world 2 points 1 hour ago

Thank you internet stranger. I'm going to do this but fuck me if I can get my family to change their settings. They don't even know they can create a poll.

Don't ask me. I made all of you admins do I don't have to answer questions like how do I make a poll. Click the + button. Yeah. The one on your fucking screen right now.

No grandpa. We are not trying to figure out who is trans. No popop none of are naxies (I hope)

Anyway, click the +. Right there. That is how you create a poll.

[–] napkin2020@sh.itjust.works 4 points 2 hours ago* (last edited 2 hours ago) (1 children)

They shouldn't have had to do this though.

[–] Quill7513@slrpnk.net 2 points 1 hour ago

there's a lot of things under fascism that shouldn't be needed

[–] Kupi@sh.itjust.works 6 points 7 hours ago* (last edited 7 hours ago)

They are similar

[–] Bazoogle@lemmy.world 17 points 12 hours ago (3 children)

You also don't need to do this on Android unless you are concerned about random people seeing the messages on your screen. Signal on Android does not use Google's push notification service

[–] Quill7513@slrpnk.net 1 points 30 minutes ago

as far as i know signal uses Google's notification service and if you want it to not you need to use Molly

[–] 0_o7@lemmy.dbzer0.com 1 points 33 minutes ago

Signal on Android does not use Google's push notification service

Source? I'm pretty sure it falls back to a different mechanism when it doesn't find google services. And that is only on the version downloaded from their website.

https://github.com/signalapp/Signal-Android/issues/13290

[–] Quexotic 3 points 1 hour ago

You most certainly do. I looked in my notification history in my founding of signal messages.

Then I turned off my notification history.

[–] RIotingPacifist@lemmy.world 27 points 14 hours ago (1 children)

It would be nice if Signal let you do this per conversation.

It's sort of a victim of its own success, I use it for both things that do and don't require opsec

[–] Quill7513@slrpnk.net 1 points 14 minutes ago

and on some level it's important for good opsec that things that don't require opsec be done with good opsec

[–] HumbleExaggeration@feddit.org 33 points 15 hours ago* (last edited 8 hours ago) (1 children)

So you are telling me an app is encrypting the shit out of every message so it can secretly delivered to another person. An then the persons phone decrypts the message and broadcasts it to an apple server, so it can get send back and make the phone go 'ding'?

Shouldnt the notification be handled inside signal somehow, so this is the only app with the decrypted message?

What is next, everything from my ram needs to go through google servers to be transmitted to my display?

[–] RunningInRVA@lemmy.world 43 points 14 hours ago

The Signal server would send a backend notification to the client app via the Apple Push Notification Service. The app is then able to wake up, at which point it fetches new messages (securely) from the Signal servers. The app then generates a local notification with a preview of the received message. iOS is then logging those messages.

[–] scytale@piefed.zip 45 points 16 hours ago* (last edited 15 hours ago) (3 children)

I learned about this a couple of months ago and I've since disabled previews in notifications. It's unfortunately the nature of how notifications are delivered to you. You should be fine by disabling message previews in your notification settings.

[–] in_my_honest_opinion@piefed.social 32 points 16 hours ago (1 children)
[–] spectrums_coherence@piefed.social 10 points 13 hours ago (2 children)

I think on android, signal do not use Google's push notification. They simple send a dummy push, and the signal app wakes up to retrive the latest message directly from signal server.

So Google never have your notification content. I am not sure if they do the same on iOS.

That being said if your attack model includes people reading your notification lock screen, then you should disable showing signal notification.

[–] 0_o7@lemmy.dbzer0.com 1 points 27 minutes ago (1 children)

I think on android, signal do not use Google's push notification.

Source?

The message preview notification is handled similarly in IOS and Android. The issue isn't people seeing the notification, it's that the content of the message being passed to the phone's launcher. Which is unencrypted.

[–] eleijeep@piefed.social 12 points 16 hours ago (1 children)

Does that actually prevent the app from sending the content through Apple’s servers or does it just prevent iOS from showing it in the notification area?

[–] Bazoogle@lemmy.world 6 points 15 hours ago

The only way apple is seeing it is when the notification is displayed. It only sees the contents of the notification itself. So it would still see who sent you a message, but it wouldn't say what it was

[–] Bazoogle@lemmy.world 10 points 15 hours ago* (last edited 15 hours ago) (1 children)

It's worth noting apps can avoid this on Android: https://tuta.com/blog/google-push-alternative#alternatives-to-google-push

Any FDroid app cannot use Firebase for push notifications since it's proprietary: https://forum.f-droid.org/t/firebase-allowed-in-fdroid-apps/7540

[–] WhyJiffie@sh.itjust.works 1 points 13 hours ago* (last edited 13 hours ago)

It's not because of push notifications. the message is not sent to firebase, just a signal that the app should do a refresh.

It's because the system saves the notifications apps posted to the notification menu.

but yes. don't use firebase push notifications if you can avoid it. use a unifiedpush based system. base signal app does not support it, only molly. there are some difficulties though with that that are unique to signal.

[–] x00z@lemmy.world 9 points 12 hours ago (1 children)

This has been done before and is already pretty well known.

[–] frongt@lemmy.zip 4 points 9 hours ago (1 children)

When I saw it hit the news before, it was because they were reading notifications off Google servers, which contained at least part of the message. Not because they were reading the device's notification history.

[–] x00z@lemmy.world 1 points 2 hours ago

That's true. Technically it's different. The end result is kind of the same though.

[–] Bazoogle@lemmy.world 12 points 15 hours ago (2 children)

This is not always the same on Android. Any app from FDroid will not use Google's push notification service because it is proprietary, meaning it violates the rules for FDroid. Signal does not use Google's notification service

[–] napkin2020@sh.itjust.works 3 points 2 hours ago

I'm pretty sure Signal has two builds: one with Google service and one without.

[–] WhyJiffie@sh.itjust.works 3 points 13 hours ago (1 children)

It's not because of push notifications. the message is not sent to firebase, just a signal that the app should do a refresh.

It's because the system saves the notifications apps posted to the notification menu.

[–] Bazoogle@lemmy.world 0 points 12 hours ago (2 children)

It’s not because of push notifications. the message is not sent to firebase, just a signal that the app should do a refresh.

Is is 100% because of firebase. Here is an example payload from firebases official document:

{
  "message":{
    "token":"bk3RNwTe3H0:CI2k_HHwgIpoDKCIZvvDMExUdFQ3P1...",
    "notification":{
      "title":"Portugal vs. Denmark",
      "body":"great match!"
    }
  }
}

https://firebase.google.com/docs/cloud-messaging/customize-messages/set-message-type

Notification history is purely local to the device. It is not sent to any servers.

[–] WhyJiffie@sh.itjust.works 3 points 2 hours ago* (last edited 2 hours ago)

that is the documentation of firebase, not signal. firebase just shows a common example there that is easy to implement for beginners and lazy devs. but developers can send whatever they want through firebase. I wouldn't be surprised if that's what facebook messenger is doing, but if a developer cares about their users privacy, they can just send a simple message through firebase, and make the app so that when receiving that, it checks for new messages by itself.

this is what the molly fork does with unifiedpush. the UP server, commonly ntfy.sh, only sees that the mollysocket server sent this to your molly client:

{"urgent": true}

Notification history is purely local to the device. It is not sent to any servers.

I did not claim so. but when your phone is confiscated, it's possible to read that out

[–] olorin99@kbin.earth 3 points 9 hours ago

Notification history is purely local to the device. It is not sent to any servers.

Yes the notifications were retrieved from the phones local storage. Firebase was not involved in anyway.

[–] woelkchen@lemmy.world 8 points 16 hours ago (3 children)

Well, of course. All notification contents go through Apple's servers (or Google's in case of Android).

[–] Bazoogle@lemmy.world 18 points 15 hours ago* (last edited 15 hours ago)

Not all, no. There are alternatives on Android:

The good news is that alternative methods for push notifications are available, namely SSE (Server Sent Events) and WebSockets.

Additionally, a new open source project, UnifiedPush is becoming increasingly popular. UnifiedPush is an open source, private alternative to Google for notifications.

https://tuta.com/blog/google-push-alternative#alternatives-to-google-push

Signal for android uses web sockets for notifications

[–] AbidanYre@lemmy.world 12 points 16 hours ago (2 children)

Why would a notification need to leave my device at all?

[–] Goodlucksil@lemmy.dbzer0.com 12 points 15 hours ago

Because it's FAANG

[–] frongt@lemmy.zip 1 points 9 hours ago

A lot of notifications originate off your device.

[–] WhyJiffie@sh.itjust.works 1 points 13 hours ago (1 children)

It's not because of push notifications. the message is not sent to firebase, just a signal that the app should do a refresh.

It's because the system saves the notifications apps posted to the notification menu.

[–] Bazoogle@lemmy.world -1 points 12 hours ago* (last edited 12 hours ago) (1 children)

As I already replied om one of your other comments:

It’s not because of push notifications. the message is not sent to firebase, just a signal that the app should do a refresh.

Is is 100% because of firebase. Here is an example payload from firebases official document:

{
  "message":{
    "token":"bk3RNwTe3H0:CI2k_HHwgIpoDKCIZvvDMExUdFQ3P1...",
    "notification":{
      "title":"Portugal vs. Denmark",
      "body":"great match!"
    }
  }
}

https://firebase.google.com/docs/cloud-messaging/customize-messages/set-message-type

Notification history is purely local to the device. It is not sent to any servers.

[–] frocalannifo@fedia.io 2 points 15 hours ago

Added the full content of the original post to the body of this thread.