Inactivity reboot" effectively puts iPhones in a more secure state by locking the user's encryption keys in the iPhone's secure enclave chip.

With iOS 18, Apple introduced a feature that causes the iPhone to reboot every three days, security researchers have confirmed (via TechCrunch). In

Apple's iOS 18.1 auto-reboot feature locks iPhones after four days, blocking easy access, but at the same time, frustrating law enforcement in forensic probes.

Last week, we saw a report of law enforcement officials being concerned that iPhones were secretly communicating with each other to force reboots, frustrating law enforcement. However, while it seems these suspicions were indeed based on a change that Apple made in a recent iOS update, it’s not what police forensic investigators first thought.

A new iPhone security feature in iOS 18 will make it tough for forensic analysts to obtain data from a locked device

Introduced with iOS 18, the new feature automatically reboots an iPhone if it's been asleep and in lock mode for an extended period of time. After a reboot, an iPhone becomes more difficult to crack since either the passcode or biometric verification is needed to unlock it.