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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[–] SnoringEarthworm@sh.itjust.works 101 points 1 week ago* (last edited 1 week ago) (6 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.)

[–] RIotingPacifist@lemmy.world 41 points 1 week ago (2 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 7 points 1 week ago (1 children)

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

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[–] rezifon@lemmy.world 3 points 1 week ago

I imagine that the signal devs viewed it as a similar concern as when you mistype your password the error message doesn’t give you any way to know if the password is wrong or if the account doesn’t exist.

If only some of your notifications are sanitized then those are the suspicious ones. If all of your notifications are sanitized then none of them are suspicious. Or, at least, they’re all equally suspicious, opaque, and unidentifiable.

[–] Bazoogle@lemmy.world 18 points 1 week 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

[–] Quexotic@infosec.pub 9 points 1 week ago

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

Then I turned off my notification history.

[–] 0_o7@lemmy.dbzer0.com 5 points 1 week 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

[–] Quill7513@slrpnk.net 5 points 1 week ago

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

[–] Kupi@sh.itjust.works 10 points 1 week ago* (last edited 1 week ago)

They are similar

[–] napkin2020@sh.itjust.works 6 points 1 week ago* (last edited 1 week ago) (1 children)

They shouldn't have had to do this though.

[–] Quill7513@slrpnk.net 6 points 1 week ago

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

[–] Crackhappy@lemmy.world 6 points 1 week 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.

[–] blargh513@sh.itjust.works 3 points 1 week ago* (last edited 1 week ago)

This is the problem, not what is shown in the per-app notifications. Don't turn on notification history.

[–] ZoteTheMighty@lemmy.zip 55 points 1 week ago (3 children)

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

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[–] scytale@piefed.zip 50 points 1 week ago* (last edited 1 week 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 34 points 1 week ago (1 children)
[–] spectrums_coherence@piefed.social 14 points 1 week ago (4 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.

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.

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[–] eleijeep@piefed.social 12 points 1 week 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 1 week 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 11 points 1 week ago* (last edited 1 week 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 6 points 1 week ago* (last edited 1 week 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.

[–] anon_8675309@lemmy.world 36 points 1 week ago (4 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.

[–] WolfLink@sh.itjust.works 9 points 1 week ago

Signal already has that setting. It’s up to the user to decide their level of convenience vs security.

[–] baggachipz@sh.itjust.works 4 points 1 week ago (2 children)

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

[–] rezifon@lemmy.world 18 points 1 week ago (6 children)

Signal has supported this for many years. Users can choose full content notifications, name only, or no-content notifications.

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[–] blargh513@sh.itjust.works 2 points 1 week ago

That's not the problem here. Showing a notification with content is not a big deal.

In the case stated here, the big deal is that the notification HISTORY was preserved after removal of Signal. That's because both Apple and Google do the same thing. They keep a notification history. Not on a per-app basis, ALL apps notification history is stored.

I know that on Androids, it is turned off by default and you can turn it on, so you get the impression that Android doesn't have this issue. I am going to guess as I do not own an apple anything that iOS has notification history turned on by default. This is the real problem. This is not anything Signal can control for unless they were to not support notifications which would render their app useless, so that's not an option.

[–] NotMyOldRedditName@lemmy.world 3 points 1 week ago* (last edited 1 week ago)

The actual notification telling you there is a message shouldn't contain the content if its sensitive, it should only carry an ID to said message, and im certain this is what signal does. Thats like the most utter basic thing about notifications.

Once that notification arrives, the system decides what to show you after fetching the message from the ID in the background. You can opt to keep that private or show it.

In this case if you opt to show it, it leaks.

[–] phx@lemmy.world 3 points 1 week ago

Yeah. It's not just signal either that could be an issue. Sure, I want my private messages to be private, but there are financial apps, business email, and many other bits of very sensitive information that could be captured in those messages

[–] HumbleExaggeration@feddit.org 32 points 1 week ago* (last edited 1 week 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 53 points 1 week 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.

[–] Bazoogle@lemmy.world 12 points 1 week ago (3 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 4 points 1 week ago

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

[–] WhyJiffie@sh.itjust.works 3 points 1 week ago (5 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.

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

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

[–] frongt@lemmy.zip 4 points 1 week 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.

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[–] TheFrirish@tarte.nuage-libre.fr 8 points 1 week ago (1 children)

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.

[–] stringere@sh.itjust.works 3 points 1 week ago* (last edited 1 week ago) (3 children)

Is there a good decent e2e messenger not in the US? Would love an alternative.

[–] forestbeasts@pawb.social 3 points 1 week ago

There's Matrix which is selfhostable but "good" is pushing it and the cryptography is a bit iffy (probably more incompetence than malice). Though selfhosting it means you don't need the end to end encryption quite as much... until the court gets involved of course.

-- Frost

[–] badgermurphy@lemmy.world 3 points 1 week ago* (last edited 1 week ago)

Good? No.

I think it is telling about Signal, though, that despite being in a privacy-unfriendly jurisdiction, federal authorities can only extract data from it when its users mess up.

I don't think you'll get much better until some of these other services mature more. Some of them seem painted into a corner where improving them further seems to involve rewriting big sections of them, like Matrix, so I am less optimistic about those.

As of now the most complete alternative (albeit controversial) is the decentralised SimpleX Chat. But it's not as easy to use as Signal.

[–] woelkchen@lemmy.world 8 points 1 week ago (5 children)

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

[–] Bazoogle@lemmy.world 18 points 1 week ago* (last edited 1 week ago) (1 children)

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

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[–] AbidanYre@lemmy.world 12 points 1 week ago (2 children)

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

[–] Goodlucksil@lemmy.dbzer0.com 12 points 1 week ago

Because it's FAANG

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Just more evidence that Apple is not that concerned about privacy as this is a hole they absolutely could close.

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