On efficient decoding for the Fuzzy Vault scheme

The Fuzzy Vault scheme was proposed as a means to improve the security of biometric technologies. However, the originally proposed Reed-Solomon (RS) decoding algorithm was not well understood and the CRC decoder, introduced as an alternative, remains the most popular in literature today. Despite its simplicity, CRC decoders contain significant flaws which motivate us to investigate the potential of RS decoders. In this paper, we discuss the role of RS codes in Fuzzy Vault and details a Berlekamp-Massey decoder as originally envisioned. However, due to the significant amount of erasures in a RS code word in Fuzzy Vault leading to poor decoder performance, we propose instead an alternate decoder based on the Euclidean algorithm, which considers the original approach to RS codes. Our results show that the RS decoder can achieve decoding speed significantly greater than any CRC decoders while maintaining information-theoretic security, which are independent of advances in computing power. We also propose an improvement to the CRC decoder as a means to evaluate the security of a Fuzzy Vault and found that many existing implementations using CRC decoding are vulnerable to brute-force attacks.