Securing fingerprint template using noninvertible ridge feature transformation

Abstract

In a biometric verification system, leakage of biometric data leads to permanent identity loss since original biometric data are inherently linked to a user. Further, various types of attacks on a biometric system may reveal the original template and utilize in other applications. To address these security and privacy concerns, cancelable biometric has been introduced. Cancelable biometric derives a protected template from the original biometric template using transformation functions and performs comparison between templates in the transformed domain. Recent approaches toward cancelable fingerprint generation either rely on aligning minutiae points with respect to singular points (core/delta) or utilize the absolute coordinate positions of minutiae points. We propose a noninvertible ridge feature transformation method to protect the original fingerprint template information. The proposed method partitions the fingerprint region into a number of sectors with reference to each minutia point employing a ridge-based co-ordinate system. The nearest-neighbor minutiae points in each sector are identified, and ridge-based features are computed. Further, a cancelable template is generated by applying the Cantor pairing function followed by random projection. We have evaluated our method with FVC2002, FVC2004, and FVC2006 databases. It is evident from the experimental results that the proposed method outperforms existing methods in the literature. Moreover, the security analysis demonstrates that the proposed method fulfills the necessary requirements of noninvertibility, revocability, and diversity with a minor performance degradation caused due to cancelable transformation.