Not a Signal Flaw: iPhone Notifications Became a Backdoor for Deleted Messages

An FBI forensic investigation showed that iPhone notification previews can retain fragments of incoming Signal messages—recoverable via forensic tools even after deletion of messages or the app—because iOS stores notification content locally. The issue is attributed to iOS notification handling (not Signal’s encryption), only affected incoming previews, and can be mitigated by disabling message previews or using tools like AuRevoir to clear cached notification data.