Biometric public key system providing revocable credentials

Abstract

A device generates a biometric public key for an individual based on both the individual's biometric data and a secret S, in a manner that verifiably characterizes both while tending to prevent recovery of either. The biometric data has a Sparse Representation and is encoded in a manner to include a component of noise, such that it is challenging to identify which locations are actually encoded features. Accordingly, the biometric data are encoded as a vector by choosing marker at locations where features are present and, where features are not present, choosing noisy data. The noisy data may be chaff bit values selected collectively from a group of (a) random values and (b) independent and identically distributed values. The biometric public key may be later used to authenticate a subject purporting to be the individual, using a computing facility that need not rely on a hardware root of trust.