Can vision (in combination with ARKit) be used to compare two faces

I am trying to authenticate a user based on a selfie. The account is created based on a picture from a company ID card. That's why it's not possible to utilize the LocalAuthentication Framework.

When they log in a

UIImagePickerController()
with
.sourceType = .camera
should take a picture and compare it to the saved picture.

I has to be done locally so Amazon Rekognition's Compare faces is unfortunately not option, the same goes for Microsoft Cognitive Services's Face API.

The Vision Frameworks has a

VNFaceObservation
class, that can detect faces, but I don't know how one would compare that to a saved one.