A Generalized Approach for Cancellable Template and Its Realization for Minutia Cylinder-Code
This work addresses the security and privacy of biometric data for applications like fingerprint recognition, though it is incremental as it extends an existing hashing technique to handle more complex template types.
The authors tackled the problem of protecting unordered and variable-size biometric templates, such as fingerprint minutiae, by proposing a generalized version of Index-of-Max (IoM) hashing called gIoM, which transforms templates into a non-invertible index domain while preserving performance on public fingerprint databases FVC2002 and FVC2004.
Hashing technology gains much attention in protecting the biometric template lately. For instance, Index-of-Max (IoM), a recent reported hashing technique, is a ranking-based locality sensitive hashing technique, which illustrates the feasibility to protect the ordered and fixed-length biometric template. However, biometric templates are not always in the form of ordered and fixed-length, rather it may be an unordered and variable size point set e.g. fingerprint minutiae, which restricts the usage of the traditional hashing technology. In this paper, we proposed a generalized version of IoM hashing namely gIoM, and therefore the unordered and variable size biometric template can be used. We demonstrate a realization using a well-known variable size feature vector, fingerprint Minutia Cylinder-Code (MCC). The gIoM transforms MCC into index domain to form indexing-based feature representation. Consequently, the inversion of MCC from the transformed representation is computational infeasible, thus to achieve non-invertibility while the performance is preserved. Public fingerprint databases FVC2002 and FVC2004 are employed for experiment as benchmark to demonstrate a fair comparison with other methods. Moreover, the security and privacy analysis suggest that gIoM meets the criteria of template protection: non-invertibility, revocability, and non-linkability.