Always-on Processor magic: How Find My works while iPhone is powered off
Update: We wrote a paper with even more technical details :) iOS 15.0 introduces a new feature: an iPhone can be located with Find My even while the iPhone is turned "off". How does it work? Is it a security concern? I saw this feature rather early on one of my iPhones with an iOS 15 beta. Here's a screenshot I took in July. The user interface changed a little bit since then. It took a bit longer until the public realized this feature exists. One needs to update to iOS 15.0, use an iPhone that has location services enabled, a logged in user account, participates in the Find My network, etc. And the weirdest thing nobody does these days: One has to turn the iPhone off. But once Twitter found out, this took off. And so did the rumors how this was implemented. Apple's Always-on Processor (AOP) There's only little public documentation about the AOP. All chips and various embedded devices Apple manufactures run a real-time operating system, called RTKitOS. The AOP on