**Abstract**

Since the security of biometric information may be threatened by network attacks, presenting individual's information without a suitable protection is not suitable for authorization. In traditional cryptographic systems, security was done using individual's password(s) or driving some other data from primary information as secret key(s). However, encryption and decryption algorithms are slow and contain time-consuming operations for transferring data in network. Thus, it is better that we have no need to decrypt an encrypted trait of an enrolled person, and the system can encrypt the user trait with the user's passwords and then compare the results with the enrolled persons' encrypted data stored in database. In this chapter, by considering wireless sensor networks and authenticating server, we introduce a new concept called "digest" and deal with its efficiency in dealing with the security problem. A "digest" can be derived from any kind of information trait through which nobody can capture any information of primary biometric traits. We show that this concept leads to the increase of the accuracy and accessibility of a biometric system.

**Keywords:** biometric authentication, wireless sensor networks, system security, cryptography, digest
