Securing cryptographic key with fuzzy vault based on a new chaff generation method

A crucial issue in the design of a cryptographic system is the problem of key management. A state-of-the-art solution to this problem is to use bio-cryptosystems, in which cryptography is combined with biometrics. In this solution, the user biometrics is used to protect the cryptographic key. A popular approach to the design of such bio-cryptosystems is the application of a fuzzy vault scheme. This so-called vault is a secure storage in which the key is hidden within the biometric data mixed up with meaningless chaff points. The most critical operation in the fuzzy vault scheme is generation of these chaff points. Experiments will show that this module is the most compute-intensive part of the whole system. This paper introduces a new chaff generation algorithm for the fuzzy vault in a bio-cryptosystem. The proposed algorithm, which is based on a circle packing mathematical theorem, is computationally less intensive than existing methods. Experimental results show that the proposed algorithm is around 100 times faster than existing methods for 200, and above, number of chaff points, and therefore, is suitable for a real-time embedded system implementation.