There’s a new mystery in the world of iPhones: Devices that, without warning, decide when they need a “pause” and reboot in total silence. There are no visible errors or warnings, just an unexpected reboot that happens without the user causing it. This peculiarity has left users and security experts confused. This seems to be the case for… well, I can’t think of who.

Fortunately, the mystery was quickly revealed. Recently, Apple introduced a feature in iOS 18.1 that went unnoticed in the update notes: “restart due to inactivity”. This feature, implemented in security components keybagd and AppleSEPKeyStore, will automatically restart the iPhone if the device remains inactive for four days, surprising many users who did not expect such behavior from their phones. Although Apple hasn’t detailed this new feature, the “idle reset” is said to be a security tool designed to add another layer of protection.

This feature directly related to key storea critical security component that manages the encryption keys used to unlock the device. Integration with key store“Idle reset” could be intended to protect users’ information in situations where the device is left inactive for several days. So if it seems that your iPhone is more interested in staying “in shape” than you, it’s not a coincidence: Apple designed this function so that the system restarts in the absence of interaction, thereby protecting the stored data, since it makes it difficult to extract it without authorized data of the same.

Of course this measure presents unforeseen challenges for the security forces. Authorities have reportedly had problems trying to access devices in custody, which reboot themselves because of the feature, complicating data collection for forensic investigations. This security boost seems to cause almost as much confusion among researchers as it does among users themselves… except, of course, among those who are able to go four days without using their phone but still have it on.

Apple has not commented on this new featurebut experts warn that this is a reflection of the company’s rigorous approach to user privacy. By introducing the “idle reset”, Apple protects personal data even in situations of prolonged inactivity, a detail that not all manufacturers take into account. But the feature reopens the debate about the balance between user privacy and the needs of law enforcement, which now faces another hurdle in its investigation.

At this time, Apple has not offered a configuration option to disable or modify the “idle restart”, but it is expected that in future iOS updates more details about its implementation are given or its capabilities are expanded. In the meantime, iPhones will continue to surprise their owners… or not as much, because at least now they’ll know why.