Cops Suspect iOS 18 iPhones Are Communicating to Force Reboots, Making Unlocking Harder

Law enforcement officials in Detroit, Michigan are warning other police officers about an alleged iPhone change that causes Apple devices stored for forensic examination to spontaneously restart, reports 404 Media.

iphone passcode green
iPhones that are undergoing examination have apparently been rebooting, which makes them harder to unlock with brute force methods, and Michigan police think that it's due to a security feature that Apple added in iOS 18. A document found by 404 Media speculates that iPhones running ‌iOS 18‌ are causing other iPhones to restart when those iPhones have been disconnected from a cellular network.

The purpose of this notice is to spread awareness of a situation involving iPhones, which is causing iPhone devices to reboot in a short amount of time (observations are possibly within 24 hours) when removed from a cellular network. If the iPhone was in an After First Unlock (AFU) state, the device returns to a Before First Unlock (BFU) state after the reboot. This can be very detrimental to the acquisition of digital evidence from devices that are not supported in any state outside of AFU.

It is believed that the iPhone devices with iOS 18.0 brought into the lab, if conditions were available, communicated with the other iPhone devices that were powered on in the vault in AFU. That communication sent a signal to devices to reboot after so much time had transpired since device activity or being off network.

After First Unlock, or AFU, denotes a device state where the owner has unlocked their device with a passcode or Face ID at least one time since it was powered on. It is easier for law enforcement to get into a device in AFU mode with ‌iPhone‌ unlocking tools from companies like Cellebrite. A restart apparently makes the process more difficult.

The digital forensics lab that noticed the issue had several iPhones in AFU state reboot, including iPhones in Airplane mode and one in a faraday box. Since a faraday box blocks all electronic signals from reaching a device, there wouldn't be a way for an ‌iPhone‌ running ‌iOS 18‌ to communicate with an ‌iPhone‌ in a functional faraday box.

The police document speculates that this is "an iOS 18.0 security feature addition" because one device running ‌iOS 18‌ also rebooted after a period of isolation and inactivity. Several other devices in the same area did not, however, restart, and there is no evidence that Apple has added a feature that causes older iPhones to reboot when in contact with an ‌iPhone‌ running ‌iOS 18‌.

Law enforcement officials recommend isolating ‌iOS 18‌ devices from other iPhones that are in an AFU state as further testing takes place.

The specific conditions that must exist for these reboots to occur is unknown and further testing and research would nee to be conducted to add more specifics to the new hurdle we are now faced with. What is known is that this new "feature" of some sort has increased the difficulty with forensically preserving digital evidence.

Matthew Green, a cryptographer and Johns Hopkins professor told 404 Media that the law enforcement officials' hypothesis about ‌iOS 18‌ devices is "deeply suspect," but he was impressed with the concept.

"The idea that phones should reboot periodically after an extended period with no network is absolutely brilliant and I'm amazed if indeed Apple did it on purpose," he said.

Update: Apple added an "inactivity reboot" feature in the iOS 18.1 update, but it does not relate to phone/wireless network state.

Note: Due to the political or social nature of the discussion regarding this topic, the discussion thread is located in our Political News forum. All forum members and site visitors are welcome to read and follow the thread, but posting is limited to forum members with at least 100 posts.

Popular Stories

iPhone 17 Pro in Hand Feature Lowgo

iPhone 17 Pro Coming Soon With These 14 New Features

Friday July 4, 2025 1:05 pm PDT by
Apple's next-generation iPhone 17 Pro and iPhone 17 Pro Max are just over two months away, and there are plenty of rumors about the devices. Below, we recap key changes rumored for the iPhone 17 Pro models. Latest Rumors These rumors surfaced in June and July:Apple logo repositioned: Apple's logo may have a lower position on the back of the iPhone 17 Pro models, compared to previous...
iphone 16 pro models 1

Here's How the iPhone 17 Pro Max Will Compare to the iPhone 17 Pro

Saturday July 5, 2025 1:00 pm PDT by
Apple should unveil the iPhone 17 series in September, and there might be one bigger difference between the Pro and Pro Max models this year. As always, the Pro Max model will be larger than the Pro model:iPhone 17 Pro: 6.3-inch display iPhone 17 Pro Max: 6.9-inch displayGiven the Pro Max is physically larger than the Pro, it has more internal space, allowing for a larger battery and...
imac video apple feature

Apple Launching These 15+ Products Later This Year

Sunday July 6, 2025 8:05 am PDT by
The calendar has turned to July, meaning that 2025 is now more than half over. And while the summer months are often quiet for Apple, the company still has more than a dozen products coming later this year, according to rumors. Below, we have outlined at least 15 new Apple products that are expected to launch later this year, along with key rumored features for each. iPhone 17 Series iPho...
iPhone Car Key Kia

Here's Which Vehicles Offer iPhone Car Keys

Sunday July 6, 2025 3:03 pm PDT by
In 2020, Apple added a digital car key feature to its Wallet app, allowing users to lock, unlock, and start a compatible vehicle with an iPhone or Apple Watch. The feature is currently offered by select automakers, including Audi, BMW, Hyundai, Kia, Genesis, Mercedes-Benz, Volvo, and a handful of others, and it is set to expand further. Apple has a web page with a list of vehicle models that ...
iOS 26 Feature

Everything New in iOS 26 Beta 3

Monday July 7, 2025 1:20 pm PDT by
Apple is continuing to refine and update iOS 26, and beta three features smaller changes than we saw in beta 2, plus further tweaks to the Liquid Glass design. Apple is gearing up for the next phase of beta testing, and the company has promised that a public beta is set to come out in July. Transparency In some apps like Apple Music, Podcasts, and the App Store, Apple has toned down the...
iPhone 17 Pro in Hand Feature Lowgo

iPhone 17 Pro to Reverse iPhone X Design Decision

Monday July 7, 2025 9:46 am PDT by
Since the iPhone X in 2017, all of Apple's highest-end iPhone models have featured either stainless steel or titanium frames, but it has now been rumored that this design decision will be coming to an end with the iPhone 17 Pro models later this year. In a post on Chinese social media platform Weibo today, the account Instant Digital said that the iPhone 17 Pro models will have an aluminum...
iphone 17 pro render majin bu

New iPhone 17 Pro Renders Highlight Apple Logo and MagSafe Design Changes

Sunday July 6, 2025 8:43 pm PDT by
New renders today provide the best look yet relocated Apple logo and redesigned MagSafe magnet array of the iPhone 17 Pro and iPhone 17 Pro Max. Image via Majin Bu. Several of the design changes coming to the iPhone 17 Pro model have been rumored for some time, such as the elongated camera bump that spans the full width of the device, with the LiDAR Scanner and flash moving to the right side. ...
Prime Day 25 Feature Warm Triad

The Best Early Prime Day Deals on Apple Products

Saturday July 5, 2025 7:22 am PDT by
Amazon is soon to be back with its annual summertime Prime Day event, lasting for four days from July 8-11, the longest Prime Day yet. As it does every year, Prime Day offers shoppers a huge selection of deals across Amazon's storefront, and there are already many deals you can get on sale ahead of the event. Note: MacRumors is an affiliate partner with Amazon. When you click a link and make a ...
airpods pro 2

AirPods Pro 3 to Help Maintain Apple's Place in Earbud Market Amid Increasing Low-Cost Competition

Thursday July 3, 2025 7:25 am PDT by
Apple's position as the dominant force in the global true wireless stereo (TWS) earbud market is expected to continue through 2025, according to Counterpoint Research. The forecast outlines a 3% year-over-year increase in global TWS unit shipments for 2025, signaling a transition from rapid growth to a more mature phase for the category. While Apple is set to remain the leading brand by...

Top Rated Comments

dustin_ Avatar
9 months ago
good stuff!
Score: 42 Votes (Like | Disagree)
adambadamh Avatar
9 months ago
Am I missing something? How would the devices be "talking" to one another to force the restarts if the device also in the faraday box exhibited the same issue?
Score: 41 Votes (Like | Disagree)
ersan191 Avatar
9 months ago
Why would they have random phones talk to each other rather than just rebooting if the phone hasn't been connected to cellular for awhile in iOS 18 itself?
Score: 41 Votes (Like | Disagree)
orbital~debris Avatar
9 months ago
Concept is cool.

But as it’s a new iOS it could easily just be a bug ('https://www.macrumors.com/2024/10/21/ios-18-1-fixes-random-restart-bug-iphone-16/'), too.
Score: 39 Votes (Like | Disagree)
now i see it Avatar
9 months ago
Ha. iPhones are crashing because of buggy software and now it’s called a security feature!
Score: 34 Votes (Like | Disagree)
anshuvorty Avatar
9 months ago
Um, maybe law enforcement, once again, misunderstands technology?
Score: 18 Votes (Like | Disagree)