Design of a cancelable biometric template protection scheme for fingerprints based on cryptographic hash functions

Abstract

Enforcing security and privacy guarantees for biometric users via protecting their unique and personalized attributes is an important area of research. There are many properties desirable in a biometric template protection scheme, but unfortunately, all of the requirements are not simultaneously fulfilled. In our work, we have tried to address this issue by proposing a cancelable framework for fingerprints which simultaneously provides satisfactory system performance, strong security guarantees, and fast matching procedure. The core of our scheme essentially pivots around the use of cryptographic hash functions which provide the adequate levels of security in the framework. Prior to the hashing stage, we have employed an effective pre-alignment technique and a hexagonal grid based quantization scheme which allows us to overcome constraint such as intra-class variability. Finally, our scheme is made cancelable through traditional salting. We tested our framework on various fingerprint databases and found that the resulting system performances were comparable with other contemporary cancelable schemes (EERs of 5.8%, 5.3%, 15.8%, 14.5% were observed for FVC2002 DB1, DB2, FVC2004 DB1, DB2 databases under the stolen token scenario). Most importantly, we perfectly fulfill the unlinkability, cancelability and diversity requirements, which are verified both theoretically and empirically.