A Delaunay triangle group based fuzzy vault with cancellability

Lack of the capability of cancellability in a biometric cryptosystem makes it impossible to be deployed broadly in real applications. This is because the compromise of a template in one application often means its loss in all other applications. To solve this problem, we equip a minutiae-based fuzzy vault with cancellability by applying a polar transformation to each Delaunay triangle group so as to enhance the security level of the biometric template. The unit of the non-invertible polar transformation is a triangle as a whole instead of a single minutiae point which makes the proposed method to be more stable and insensitive to non-linear distortion. Experimental results on public fingerprint databases FVC2002 DB1 and DB2 demonstrate the valid of the proposed method.