The FBI has gained the ability to decrypt remote messages in Signal

Brief summary of the news material

The Federal Bureau of Investigation (FBI) was able to recover copies of incoming messages from the Signal messenger that had already been deleted within the app itself. This became possible because Apple stores notifications about new messages in the iPhone’s internal memory every time they appear on the lock screen.

How it happened
1. Saving notifications

With the option enabled to display the sender’s name and a text fragment in the Signal notification, the device automatically remembers this data even after the app is deleted.

2. Recovery from system memory

The investigation extracted the required messages directly from the phone’s internal memory, not through the messenger itself. As a result, only incoming correspondence was recovered – outgoing messages were already unavailable in Signal.

3. Legal proceedings

The court was shown these recovered messages, which had disappeared from the app by that time. One of the sources present at the hearing stated that the prosecution presented detailed data on messages with automatic deletion and those already removed in Signal.

4. Witness testimony

Some messages were obtained from the phone of a witness cooperating with the investigation.

Signal notification settings
In the app you can configure the visibility of information in notifications:

- Settings → Notifications

- *Name, Content and Actions* – sender’s name, part of the text, and actions

- *Name Only* – only the sender’s name

- *No Name or Content* – hide all information completely

When choosing the first two options, the iPhone stores this data in memory even after the messenger is deleted.

Thus, thanks to how Apple’s notification system works, the FBI was able to access Signal messages that had already been removed from the app itself.