Wall Street Journal:

Forget fiddling with passwords or even fingerprints; forget multiple layers of sign-in; forget credit cards and, eventually, even physical keys to our homes and cars. A handful of laptops and mobile devices can now read facial features, and the technique is about to get a boost from specialized hardware small enough to fit into our phones.

Using our faces to unlock things could soon become routine, rather than the purview of spies and superheroes.

And:

Depth-sensing technology, generally called “structured light,” sprays thousands of tiny infrared dots across a person’s face or any other target.

By reading distortions in this field of dots, the camera gathers superaccurate depth information. Since the phone’s camera can see infrared but humans can’t, such a system could allow the phone to unlock in complete darkness.

And:

Teaching our phones what our faces look like will be just like teaching them our fingerprints, says Sy Choudhury, a senior director at Qualcomm responsible for security and machine-intelligence products. An image of your face is captured, relevant features are extracted and the phone stores them for comparison with your face when you unlock the phone.

As with fingerprint recognition, the facial images are securely stored only on the device itself, not in the cloud. History — from Apple’s battles with domestic law enforcement over unlocking iPhones to Amazon’s insistence that the Alexa doesn’t upload anything until it hears its wake word — suggests companies will use this privacy as a selling point.

My fingerprints don’t change, but moisture, sweat, and dirt can make my fingerprints unreadable to Touch ID. I wonder if a haircut, beard trim, shift in makeup patterns will have a similar impact on facial recognition.

Fascinating read.