Unconditionally provably secure cancelable biometrics based on a quotient polynomial ring

The Correlation Invariant Random Filtering (or CIRF) is an algorithm for cancelable biometrics, and known to have provable security. However, the security proof requires a strong assumption with regard to biometric features, which is rarely satisfied in practice. In this paper we examine the security of the CIRF when the assumption is not satisfied, and show that there are problems in secrecy of the feature and diversity of cancelable templates. To address these problems, we interpret the CIRF from an algebraic point of view, and generalize it based on a quotient polynomial ring. Then we prove several theorems which derive a new transformation algorithm for cancelable biometrics. The proposed algorithm has provable security without any condition of biometric features.