Apple’s iOS ‘Inactivity Reboot’ feature could have consequences for thieves and police
Apple recently introduced a new security feature with the iOS 18.1 update that was rolled out to users on October 28 and could prove to be troublesome for thieves and law enforcement alike. According to a report, police officials in the US noticed that some iPhone models saved for forensics were restarting on their own, making it much more difficult to bypass the smartphone’s security. A security researcher has confirmed that the restart was due to a new feature added to iOS 18.
iOS 18.1 introduces the ‘Inactivity Restart’ feature on iPhone
According to one report by 404 Media, Detroit police officials discovered that some iPhone units that were in storage and awaiting forensic examination were rebooting, making it more difficult to unlock those devices using tools designed to access in seized devices.
The publication also referenced a Michigan police document suggesting that Apple had introduced a feature that allowed an iPhone to “communicate” with other devices, signaling them to restart. However, this theory was debunked after a security researcher delved into the iOS 18.2 code
Security researcher Jiska (@jiska@chaos.social) explains it in a after on Mastodon that Apple has actually added a feature called “idle restart” that doesn’t seem to have anything to do with the phone’s network status. Instead, the feature is designed to restart any iPhone running iOS 18.1 if it hasn’t been unlocked for a while.
How Apple’s ‘Inactivity Reboot’ feature affects thieves and law enforcement
Apple encrypts user data on a smartphone in two states: before initial unlock (BFU) and after initial unlock (AFU). The first is the condition where an iPhone has restarted and the handset can only receive calls. This is an enhanced security mode, which is lowered when the user unlocks it for the first time and enables support for Face ID or Touch ID.
An iPhone will remain in AFU mode until a restart, which means law enforcement (or thieves) can use specific tools (from companies like Cellebrite or GrayKey) designed to unlock the device and access its contents . However, when an iPhone is in the BFU state, it is much more difficult for these tools to access the device using brute force techniques.
This isn’t the first time Apple has introduced a feature that protects the iPhone from unauthorized access. After the company refused to unlock an iPhone for the FBI in 2016 (the FBI ended up using a third party to unlock the phone), the company added a setting that disabled USB debugging on its smartphones,
