Combination of symmetric hash functions for secure fingerprint matching

Fingerprint based secure biometric authentication systems have received considerable research attention lately, where the major goal is to provide an anonymous, multipliable and easily revocable methodology for fingerprint verification. In our previous work, we have shown that symmetric hash functions are very effective in providing such secure fingerprint representation and matching since they are independent of order of minutiae triplets as well as location of singular points (e.g. core and delta). In this paper, we extend our prior work by generating a combination of symmetric hash functions, which increases the security of fingerprint matching by an exponential factor. Firstly, we extract k-plets from each fingerprint image and generate a unique key for combining multiple hash functions up to an order of (k-1). Each of these keys is generated using the features extracted from minutiae k-plets such as bin index of smallest angles in each k-plet. This combination provides us an extra security in the face of brute force attacks, where the compromise of few hash functions as well do not compromise the overall matching. Our experimental results suggest that the EER obtained using the combination of hash functions (4.98%) is comparable with the baseline system (3.0%), with the added advantage of being more secure.