iOS 18.1 quietly adds a 'Restart on Inactivity' feature that restarts locked iPhones after a certain period of time

It turns out that Apple has quietly added a feature called 'inactivity reboot' to iOS 18.1 that automatically reboots a locked iPhone after a certain period of time has elapsed.

Apple Quietly Introduced iPhone Reboot Code Which is Locking Out Cops

Here's why iPhones were rebooting themselves, according to experts

iOS 18.1 boosts security with inactivity reboot feature
https://appleinsider.com/articles/24/11/09/iphones-on-ios-181-will-automatically-reboot-and-lock-down-after-being-idle-for-a-while

It has been reported that devices may randomly reboot when using iOS 18, but Apple's addition of the 'inactivity reboot' feature to iOS 18.1 has revealed that the random reboots may have been caused by this feature.

Although Apple has not officially announced that iOS 18.1 includes a feature that automatically restarts an iPhone after it has been locked for a certain period of time, experts have reported that they have confirmed the addition of the code.

Apple indeed added a feature called 'inactivity reboot' in iOS 18.1. This is implemented in keybagd and the AppleSEPKeyStore kernel extension. It seems to have nothing to do with phone/wireless network state. Keystore is used when unlocking the device. https://t.co/ONZuU9zVt2 https://t.co/4ORUqR6P6N pic.twitter.com/O3jijuqpN0

— Jiska (@naehrdine) November 8, 2024

Initially, some thought that the phone would reboot on its own because it had lost connectivity, but researchers found code for a timer that counts inactivity time, and it was found that the timer only counts how long it has been since the phone was last unlocked, regardless of whether it is charged or not, or whether it is connected to a network. The time until the phone reboots is 96 hours, or four full days.

After booting up an iPhone, the security level differs between the 'Before First Unlock (BFU)' and 'After First Unlock (AFU)' states. In the BFU state, biometric authentication is turned off and data is fully encrypted, making it very difficult to extract confidential files.

Therefore, even if your iPhone is stolen or lost and there is a risk that your data may be stolen, if it is automatically restarted, the risk of user data being stolen is greatly reduced, thereby increasing safety.

While this may be a hassle for police and law enforcement agencies trying to seize and investigate devices that may have been used in crimes, it is likely to be of help to iPhone users.