Apple has created a complicated new system to enable Face ID to be near impossible to fool. The TrueDepth Camera system has a 1 in a million chance of unlocking for anyone other then the owner, such as an identical twin.
The other security system Apple uses on iPhones and iPads, is Touch ID, which scans your fingerprint. This is also enabled on new MacBook Pro's with the Touch Bar's fingerprint scanner. Touch ID has a 1 in 50,000 rate of false recognition, while Face ID has a 1 in one million rate of false recognition, meaning Face ID is far more secure.
The TrueDepth Camera system at the top of the iPhone X uses a complicated integration of separate features rolled in to one module, for the purpose of Face ID.
How does it work?
First, an emitter shines infrared light on your face. Next, a dot projector covers your face with 30,000 dots of invisible light. Then, a sensor scans the dot pattern to create a mathematical model of the dots projected on to the 3D surface of your face. Next, a sensor takes an infrared photo of your face. Then, a camera is used to capture an image of your face, and is checked to ensure your eyes are open and that you're looking directly at your phone. While this is happening, sensors are checking depth maps, separating your face from the background, and checking the dot-projected wireframe of your face against the stored results. It can even authenticate whether you're you, from slightly different angles, based on its original scans of your face.
The system can make allowances for subtle changes in your appearance, such as slightly longer or shorter hair, facial hair, glasses, hats, and other common items. It can tell whether its looking at a living person or at a photo of a person, and can tell the difference between a living human and a 3D mask. Apple has not revealed how this is possible, although it is possible that the system takes a number of scans or photos of your face to check for blinking, heat, eye movement, and other common movements that wouldn't be possible if it were looking at a photo or a mask.
After making sense of all this information in less than one second, it double-checks the results against those stored in the secure enclave in a chip on the phone. the results are not shared with Apple servers or sent over the internet.
If the result is a positive match, and the system is sure that you are really you, it will unlock the phone. Next, simply slide up and your phone is ready to use.
PrimeSense
Apple purchased a European company called PrimeSense, who invented the technology that enables the depth perception. This is the same company that licensed technology to Microsoft, for use in the original Xbox Kinect camera system. While Microsoft's involvement pre-dates that of Apple, Microsoft owns or licences some similar technology which is still used for the WIndows Hello facial recognition in Windows. Microsoft has recently ended development of the Kinect.
Face ID and...
The TrueDepth Camera system and Face ID are set to completely replace Touch ID starting in 2018.
More Apple devices will be updated to include the required cameras and sensors, including future iPad Pro's and future iterations of the iPhone beyond the iPhone X.
iPhone 7 and iPhone 8 will retain Touch ID, along with current versions of the iPad line.
Some Mac computers that were expected to receive Touch ID may no longer get Touch ID, in anticipation of a full roll-out of Face ID. Touch ID was going to come to iMacs via a fingerprint scanner integration on a keyboard, mouse, or touchpad, however this may be scrapped in favour of integrating a Face ID-capable camera on iMacs and MacBooks.
Until next time,
Xavier Zymantas
XYZ Media Group