Despite the fact that Apple has already shared a lot of information about the Face ID feature on the iPhone X, primarily through its software engineering chief Craig Federighi, the company has now consolidated the information into a support document and an in-depth security white paper that was released yesterday.
Federighi’s interviews have already covered the majority of what is in the support document but it still allows all questions and concerns to be addressed in one place. It outlines the way that Face ID works and the conditions in which it works such as in the dark, with sunglasses and with hats as well as how it is set up using security information and the conditions that could lead to the feature being disabled:
– The device has just been turned on or restarted.
– The device hasn’t been unlocked for more than 48 hours.
– The passcode hasn’t been used to unlock the device in the last six and a half days and Face ID hasn’t unlocked the device in the last 4 hours.
– The device has received a remote lock command.
– After five unsuccessful attempts to match a face.
– After initiating power off/Emergency SOS by pressing and holding either volume button and the side button simultaneously for 2 seconds.
Apple has already explained that Face ID will adapt to any changes in appearance but the document provides more comprehensive information. For example, if there is a major change in appearance such as the disappearance of a beard, Apple will require a passcode and then update the new facial data once your identity has been confirmed.
The white paper also covers privacy and explains once more that Face ID is just like Touch ID in a sense that is protected by a Secure Enclave, using years of established security protocols.
It explains in more detail how the TrueDepth camera works alongside the A11 Bionic processor to accurately identify a face:
To counter both digital and physical spoofs, the TrueDepth camera randomizes the sequence of 2D images and depth map captures, and projects a device-specific random pattern. A portion of the A11 Bionic chip’s neural engine–protected within the Secure Enclave–transforms this data into a mathematical representation and compares that representation to the enrolled facial data. This enrolled facial data is itself a mathematical representation of your face captured across a variety of poses.
All in all, anyone who plans to buy an iPhone X who has concerns about the security of Face ID should take a look at the document which will answer any questions. The new device is available to the public from November 3.