Biometric encryption based on a fuzzy vault scheme with a fast chaff generation algorithm

Fuzzy vault is a scheme that complements traditional cryptographic security systems by combining it with biometric authentication to overcome the security vulnerability inherent in cryptographic key storage. Biometric encryption systems based on fuzzy vault scheme are suitable for stand-alone security and authentication devices in the form of system-on-chip (SoC). However, the current fuzzy vault scheme has too many compute-intensive processes to make this feasible for SoC implementation. The most critical but compute-intensive function in the fuzzy vault scheme is the chaff generation which produces noise (chaff) points that hide the valid points inside the vault template. In this paper, we propose a new chaff generation algorithm which is computationally fast and viable for hardware acceleration by employing simple arithmetic operations. Complexity study shows that our algorithm has a complexity of O(n^2), which is a significant improvement over the existing method that exhibits O(n^3) complexity. Our experimental results show that, to generate 500 chaff points, the proposed algorithm gives a performance speed-up of over 140 times over existing Clancy's algorithm. With the new chaff generation algorithm, it becomes much more amenable to implement the fuzzy vault scheme in the resource-constrained environment of system-on-chip.