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FBI used iPhone notification data to retrieve deleted Signal messages

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Re: FBI used iPhone notification data to retrieve deleted Signal messages

#311

Post by eggnet »

commandersaki wrote: post #299
upofadown wrote: post #180

Putting on my user hat... "OK. Signal has forward secrecy. So messages are gone after I receive them. Great!" Oh, you didn't turn on disappearing messages? Oh, right, then forensic tools like Cellebrite can get them. You have to turn on disappearing messages. The default is off. Oh, you did turn on disappearing messages? We send the messages in notifications. So the OS can keep them. Turns out Apple was doing that. T…

We send the messages in notifications. So the OS can keep them. Turns out Apple was doing that. There is an option you can turn on to prevent that. It is off by default. At least on my iPhone the default is to preview messages only when unlocked [0]. This user went out of their way to show previews in a locked state which meant it was vulnerable by digital acquisition without unlock code. [0] https://files.catbox.moe…

That doesn’t solve the problem. You have to configure Signal to not send the information in the notification.

Re: FBI used iPhone notification data to retrieve deleted Signal messages

#312

Post by jacquesm »

david_shaw wrote: post #263
OutOfHere wrote: post #241

Earlier quoted context omitted.

There is nothing secure about sending encrypted content to notifications. If it were secure, it would only notify that there is a message, with no details included.

> If it were secure, it would only notify that there is a message, with no details included. You're right. This is configurable via settings, but is not the default state. That said: if I can get friends and family to use Signal instead of iMessage, that gives me the opportunity to disable those notifications and experience more security benefits. But I agree with your point: most people think that Signal is bulletpr…

You only control one side of any conversation.

Re: FBI used iPhone notification data to retrieve deleted Signal messages

#313

Post by chinathrow »

pipe01 wrote: post #194
chinathrow wrote: post #18

On Android, when I use WhatsApp and have notifications for groups turned off, I can still see that they arrive briefly and then get removed (the icon top left vanishes). I wonder often, if this is a way to push all group message content into an unencrypted data trace as well - for the same use case.

I've never seen this happen, maybe you're seeing the "Fetching messages" notification that sometimes pops up for a second?

No, it's exactly when new messages for muted groups arrive. Confirmed via WhatsApp Web.

Re: FBI used iPhone notification data to retrieve deleted Signal messages

#314

Post by jacquesm »

anon84873628 wrote: post #251
OutOfHere wrote: post #241

Earlier quoted context omitted.

There is nothing secure about sending encrypted content to notifications. If it were secure, it would only notify that there is a message, with no details included.

Once again there is a trade off between security and user convenience. If security is the main differentiator then app should start in the most secure mode possible. Then allow users to turn on features while alerting them to the risks. Or at least ask users at startup whether they want "high sec mode" or "convenient mode". As the app becomes more popular as a general messaging replacement, there will be a push towar…

Exactly, but, sooner or later the cost of support overcomes the need for security, that's what is driving this. Popularity is the main reason signal is now less secure than it was in the past.

Re: FBI used iPhone notification data to retrieve deleted Signal messages

#315

Post by Thorrez »

leesalminen wrote: post #168
Thorrez wrote: post #152

Earlier quoted context omitted.

AIUI, Signal push notifications just saying a message was received. Signal then fetches the E2E encrypted message from the server and decrypts it locally. So Apple/Google cannot read the messages, nor can Signal servers.

AIUI, Signal decrypts the E2EE message locally, but then sends the decrypted message to iOS in order to display the notification to the user. iOS then stores this data and it persists after the user dismisses the notification. This makes sense and there's really no way around it without a change from Apple. If iOS is going to show the user a Signal notification with the decrypted message in the notification body, the…

I agree. My point is that this isn't an "obvious hole in the whole E2E encryption setup", because no network actor (e.g. Google, Apple, Signal servers) can read the data.

This "hole" in E2E is the same as any malware on the device. If the device cannot be trusted, no form of E2E will work. The E2E encryption is functioning properly. The problem here is completely unrelated to E2E encryption. E.g. you could have a personal notes app that makes no network traffic, but generates notifications occasionally regarding your notes, and it could have this same problem, even though no messages are sent over the network, and in fact the phone could have all networking capabilities disabled and still have this problem.

>This makes sense and there's really no way around it without a change from Apple.

There is a bit of a workaround: Signal has a setting to not put message content in the notification. That fixes this AIUI.

Re: FBI used iPhone notification data to retrieve deleted Signal messages

#316

Post by commandersaki »

eggnet wrote: post #311
commandersaki wrote: post #299

Earlier quoted context omitted.

We send the messages in notifications. So the OS can keep them. Turns out Apple was doing that. There is an option you can turn on to prevent that. It is off by default. At least on my iPhone the default is to preview messages only when unlocked [0]. This user went out of their way to show previews in a locked state which meant it was vulnerable by digital acquisition without unlock code. [0] https://files.catbox.moe…

That doesn’t solve the problem. You have to configure Signal to not send the information in the notification.

“We learned that specifically on iPhones, if one’s settings in the Signal app allow for message notifications and previews to show up on the lock screen, [then] the iPhone will internally store those notifications/message previews in the internal memory of the device,” a supporter of the defendants who was taking notes during the trial told 404 Media

Doesn't indicate this is an issue when you have it set to preview when unlocked.

Re: FBI used iPhone notification data to retrieve deleted Signal messages

#317

Post by wqaatwt »

dist-epoch wrote: post #231
upofadown wrote: post #180

Putting on my user hat... "OK. Signal has forward secrecy. So messages are gone after I receive them. Great!" Oh, you didn't turn on disappearing messages? Oh, right, then forensic tools like Cellebrite can get them. You have to turn on disappearing messages. The default is off. Oh, you did turn on disappearing messages? We send the messages in notifications. So the OS can keep them. Turns out Apple was doing that. T…

Use SimpleX if you really want a secure messenger. Endorsed by Whonix, which in endorsed by Snowden. https://www.whonix.org/wiki/Chat#Recommendation

> endorsed by Snowden.

Who is endorsed by the Russian government

Re: FBI used iPhone notification data to retrieve deleted Signal messages

#318

Post by lolc »

satvikpendem wrote: post #291
lolc wrote: post #290

Earlier quoted context omitted.

Not clear what your point is. The Signal server wakes up the app via an empty message. At most the info this conveys is that a Signal app got a message to pull.

My point is there is no reasonable way to remove oneself from Google and Apple even with a fully custom application, they control the notification servers for their devices.

Yea sorry I didn't follow the thread properly.

Re: FBI used iPhone notification data to retrieve deleted Signal messages

#319

Post by [deleted] »

jhatemyjob wrote: post #310
SergeAx wrote: post #273

Earlier quoted context omitted.

A system like the one in "my phone's operating system". Do you assume that "Alphabet boys" have access to all parts of all Android file systems of all the phones ever produced?

I'm sorry but I'm having a really hard time understanding what you're saying. The first sentence I cannot understand at all. As for the second sentence, I think you might be confused about my usage of the term "Alphabet boys", which is slang for the intelligence agencies: https://youtu.be/lLf84LPzlVc?t=61 it seems like you thought I was referring to Google's parent company.

[deleted]

Re: FBI used iPhone notification data to retrieve deleted Signal messages

#320

Post by ranger_danger »

gumby271 wrote: post #199
nixosbestos wrote: post #70

Um. Android has notification history also and I see no similar ability to hide notification content from the system ...

In the Signal app itself there's an option to hide the message body or both the sender and body, that way the OS wont have anything to store in the history.

How do we know the message contents aren't still sent to google? Has someone verified this anywhere publicly?
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