Galaxy Note8: What's the basic principle of iris scanning?

The iris recognition feature uses the unique characteristics of your irises, such as their shape
and pattern, to strengthen the security of your device.

Your iris data can be used for various authentication purposes. After registering your irises,

you can set the device to use your irises for the following features such as Screen lock,

Web sign-in, Verify Samsung account, Secure Folder, Samsung Pay. 

The following steps are done when IRIS scan is used.

 1. Capturing the iris (with IR Camera)

 2. Extract pattern of iris and convert into digital form. The digital pattern is being saved and registered.

3. When using it to unlock, the phone scans the Iris and compare it with registered one and authenticate

The device will unlock once it is confirmed to be of the same digital information.