Researchers at the University of Michigan (UMI) believe that Apple's new iPhone software has a novel security feature. It presents that the feature may automatically reboot the phone if it has been unlocked for 72 hours without being unlocked. 

As 404 Media reported later, a new technology called "inactivity reboot" was introduced in iOS 18.1, which forces devices to restart if their inactivity continues for more than a given period.  Aside from the Inactivity Reboot feature, Apple continues to enhance its security framework with additional features as part of its ongoing security enhancements. Stolen Data Protection is one of the features introduced in iOS 17.3. It allows the device to be protected against theft by requiring biometric authentication (Face ID or Touch ID) before allowing it to change key settings. 

There are various methods to ensure that a stolen device is unable to be reconfigured easily, including this extra layer of security. With the upcoming iOS 18.2 update, Apple intends to take advantage of a feature called Stolen Data Protection, which is set to be turned off by default to avoid confusing users. However, Apple plans to encourage users to enable it when setting up their devices or after a factory reset to maintain an optimal user experience. 

As a result, users will be able to have more control over the way their personal information is protected. Apple has quietly introduced a new feature to its latest iPhone update that makes it even harder for anyone to unlock a device without consent—whether they are thieves or law enforcement officers. With this inactivity reboot feature, Apple has made unlocking even more difficult for anyone. When an iPhone has been asleep or in lock mode for an extended period, a new feature is introduced with iOS 18.1 will automatically reboot it in addition to turning it off. 

A common problem with iPhones is that once they have been rebooted, they become more difficult to crack since either a passcode or biometric signature is required to unlock them. According to the terms of the agreement, the primary objective of this measure is to prevent thieves (or police officers) from hacking into smartphones and potentially accessing data on them. There is a new "inactivity reboot" feature included in iOS 18 that, according to experts who spoke to 404 Media, will restart the device after approximately four days of dormancy if no activity is made.

A confirmation of this statement was provided by Magnet Forensics' Christopher Vance in a law enforcement group chat as described in Magnet Forensics' Christopher Vance, who wrote that iOS 18.1 has a timer which runs out after a set amount of time, and the device then reboots, moving from an AFU (After First Unlock) state to a BFU (Before First Unlock) state at the end of this timer. According to 404 Media, it seems that the issue was discovered after officers from the Detroit Police Department found the feature while investigating a crime scene in Detroit, Michigan.

When officers were working on iPhones for forensic purposes in the course of their investigation, they noticed that they automatically rebooted themselves frequently, which made it more difficult for them to unlock and access the devices. As soon as the devices were disconnected from a cellular network for some time, the working theory was that the phones would reboot when they were no longer connected to the network.  

However, there are actually much simpler explanations that can be provided for this situation. The feature, which AppleInsider refers to as an inactivity reboot, is not based on the current network connection or the state of the battery on the phone, which are factors that may affect the reboot timer. The reboot typically occurs after a certain amount of time has elapsed -- somewhere around 96 hours in most cases.  Essentially, the function of this timer is identical to the Mac's hibernation mode, which is intended to put the computer to sleep as a precaution in case there is a power outage or the battery is suddenly discharged. 

During the BFU state of the iPhone, all data on the iPhone belongs to the user and is fully encrypted, and is nearly impossible for anyone to access, except a person who knows the user's passcode to be able to get into the device. However, when the phone is in a state known as "AFU", certain data can be extracted by some device forensic tools, even if the phone is locked, since it is unencrypted and is thus easier to access and extract.  

According to Tihmstar, an iPhone security researcher on TechCrunch, the iPhones in these two states are also known as "hot" devices or "cold" devices depending on their temperature.  As a result, Tihmstar was making a point to emphasize that the majority of forensic firms are focusing on "hot" devices in an AFU state as they can verify that the user entered the correct passcode in the iPhone's secure enclave at some point. A "cold" device, on the other hand, is considerably more difficult to compromise because its memory can not be easily accessed once the device restarts, so there is no easy way to compromise it.

The law enforcement community has consistently opposed and argued against new technology that Apple has implemented to enhance security, arguing that this is making their job more difficult. According to reports, in 2016, the FBI filed a lawsuit against Apple in an attempt to force the company to install a backdoor that would enable it to open a phone owned by a mass shooter. Azimuth Security, an Australian startup, ultimately assisted the FBI in gaining access to the phone through hacking. 

These developments highlight Apple’s ongoing commitment to prioritizing user privacy and data security, even as such measures draw criticism from law enforcement agencies. By introducing features like Inactivity Reboot and Stolen Data Protection, Apple continues to establish itself as a leader in safeguarding personal information against unauthorized access. 

These innovations underscore the broader debate between privacy advocates and authorities over the balance between individual rights and security imperatives in an increasingly digitized world.