With iOS 11.4.1, Apple introduced USB Restricted Mode. This is intended to make the work of tools such as GrayKey or similar tools for unlocking iPhones significantly more difficult.
After a security flaw in the function became known, Apple seems to have fixed it with the latest developer beta of iOS 12 – that’s what developers are reporting. Security researchers from Elcomsoft previously found a cost-effective way to circumvent the lock. The 60-minute countdown, which was supposed to ensure that the USB port was automatically deactivated for external devices after one hour from the last device release, could apparently be reset.
All you needed was a 40 euro Lightning to USB 3 camera adapter from Apple. (About the report: “USB Restricted Mode” – again not safe)
Apple acts rigorously
Apple seems to have completely abolished the hour limit in iOS 12 Beta 4. If you now want to use hardware via the Lightning port, the iPhone must first be unlocked, as long as the "USB Restricted Mode" is active. Only charging the battery is possible when the device is locked. If you want to use external devices without permission, you can change this in the system settings.
Whether Apple will adopt this methodology in the final version of iOS 12 remains unclear for the time being.