Thread by @1nsane_dev

I wanted to share with you some details about the #TouchID security system, implemented across 2013 #iPhone 5S all the way up to 2020 iPhone SE 2nd Gen (and many #iPad and #MacBook models as well).

1/ TouchID is a security system handled by Secure Enclave Professor (SEP).

2/ it has seen improvements over the years.
Technically speaking, TouchID is nothing more than an under-glass Camera that captures pictures of the finger used to unlock the device. The metal ring around the button is capable of detecting the finger.

3/ Apple is probably working on a solution to move it under display.
Left: under display TouchID patent (Apple)
Right: Touch ID original patent

4/ Internally, during its setup, the sensor captures various pictures of the finger, helping the user exposing each part of the finger.

5/ pictures are then stored and used to compare the sensor’s input during an unlock tentative (or any other operation that requires and supports this authentication method).
Eventually it will find a match and update the stored informations to increase success rate over the time.

6/ Here is an internal application that shows the match process and the related update. TouchID has been and is nowadays a great #security feature; the sensor is uniquely paired to the device, in order to prevent hardware attacks. More soon, as well on #FaceID.