Soft generation of secure biometric keys

Abstract

A new, soft two-level approach for the generation of multiple and revocable biometric keys, adapted to the analog nature of biometric signals, is proposed. It consists of a novel soft code-offset construction for the Euclidean metric, applied at the first level, and a code-redundancy construction for the Hamming metric, preferably based on a Reed-Solomon code, applied at the second level. The Shannon entropy analysis shows that the new construction achieves maximal possible security. It is also shown that the previously proposed constructions for the Euclidean metric are vulnerable to biometric template reconstruction in the multiple-key scenario. © Springer-Verlag Berlin Heidelberg 2007.