One of the major tentpoles for Apple is security and user privacy, but over the last few months there has been a lot of attention paid to devices and firms that aim to bypass those goals, including the GrayKey box from Grayshift.
But it looks like iOS 11.4 might be introducing yet another step in the overall security process for Apple. What’s known as “USB Restricted Mode” is a new element being added to iOS 11.4, which is currently being beta tested by Apple. As initially reported today by MacRumors, based on the findings made by Elcomsoft, the new feature will effectively disable the Lightning port on a supported device after seven days of the device not being unlocked.
That doesn’t mean the device can’t be charged anymore if that seven day mark is reached, though. Elcomsoft was able to confirm that USB Restricted Mode is indeed activated in iOS 11.4, and that after the expiration date for the timeframe is reached the Lightning port is no longer capable of accessing data on the device.
At that point, the Lightning port is only good for charging. Until the device is unlocked again, of course, after which the Lightning port can be used as normal.
“At this point, it is still unclear whether the USB port is blocked if the device has not been unlocked with a passcode for 7 consecutive days; if the device has not been unlocked at all (password or biometrics); or if the device has not been unlocked or connected to a trusted USB device or computer.
In our test, we were able to confirm the USB lock after the device has been left idle for 7 days. During this period, we have not tried to unlock the device with Touch ID or connect it to a paired USB device. What we do know, however, is that after the 7 days the Lightning port is only good for charging.”
This will put a very direct time limit on access to an iPhone or other iOS device. This won’t completely stop cracking devices, like the aforementioned GrayKey, from accessing an accessible iPhone, not entirely. But it will put a time restriction on the whole process.
As noted in the original report, Apple is aiming to make USB Restricted Mode just one more step in the overall security process, saying in an official support document that “To improve security, for a locked iOS device to communicate with USB accessories you must connect an accessory via Lightning connector to the device while unlocked – or enter your device passcode while connected – at least once a week.”
It is worth pointing out that this isn’t the first time that Apple has implemented this idea. USB Restricted Mode was first introduced with iOS 11.3, but Apple cut it from the public release. So it is possible that Apple will do the same thing with iOS 11.4, when that software is ready for public download.