Great complement to my interview with Federighi on the same topic yesterday, including some privacy-related points I didn’t think to ask about:
When it comes to customers — users — Apple gathers absolutely
nothing itself. Federighi was very explicit on this point.
“We do not gather customer data when you enroll in Face ID, it
stays on your device, we do not send it to the cloud for training
data,” he notes.
There is an adaptive feature of Face ID that allows it to continue
to recognize your changing face as you change hair styles, grow a
beard or have plastic surgery. This adaptation is done completely
on device by applying re-training and deep learning in the
redesigned Secure Enclave. None of that training or re-training is
done in Apple’s cloud. And Apple has stated that it will not give
access to that data to anyone, for any price.