Secure dynamic signature-crypto key computation

Biometric-key computation is a process of converting a piece of live biometric data into a key. Among the various biometrics available today, the hand signature has the highest level of social acceptance. The general masses are familiar with the use of handwritten signature by means of verification and acknowledgement. On the other hand, cryptography is used in multitude applications present in technologically advanced society. Examples include the security of ATM cards, computer networks, and e-commerce. The signature crypto-key computation is hence of highly interesting as it is a way to integrate behavioral biometrics with the existing cryptographic framework. In this chapter, we report a dynamic hand signatures-key generation scheme which is based on a randomized biometric helper. This scheme consists of a randomized feature discretization process and a code redundancy construction. The former enables one to control the intraclass variations of dynamic hand signatures to the minimal level and the latter will further reduce the errors. Randomized biometric helper ensures that a signature-key is easy to be revoked when the key is compromised. The proposed scheme is evaluated based on the 2004 signature verification competition (SVC) database. We found that the proposed methods are able to produce keys that are stable, distinguishable, and secure.