The personnel authentication is the basic necessity for faithful access of critical information
by the genuine user. Such authentication can be performed either with traditional
means or with biometrics. The traditional means of authentication, i.e. personnel identification
number (PIN), keys, and passwords, have been used since long time
. However, these means may be forgotten and copied. Therefore, traditional
means are being replaced by biometrics authentication system. The term Biometrics is
originated from the Greek words "Bio (life)" and "Metrics (measurements)" which corresponds
to a measurement carried out using biological attributes.
In fact, biometrics are the type of idiosyncrasy, which are used to discriminate the humans.
Since biological attributes (biometrics) are unique for each individual, it would
be suitable to authenticate humans. Now a days, the biometrics are being employed
in securing many real time applications. The face, fingerprint, palmprint, and iris are
the common biometric traits, which are being used to ensure the security of airports,
gadgets, financial transaction, and imperative information.


The humans have several biometric traits in which some attributes are apparent to
all and some are obscured. The face, fingerprint, palmprint, and ear are the apparent biometric traits whereas palm veins, and DNA are the obscured biometric traits. Biometric
traits are classified into two broad categories, i.e. behavioural and physiological
(Jain et al., 2011) biometric traits. Figure 1.1 shows example images of different biometric
Traits. Physiological biometric traits include ear, face, iris, fingerprint, knuckle, and palmprint, whereas behavioral biometric traits include human gait and signature.
Since humans have several biological attributes, it must have certain properties in order
to recognize itself as a biometric trait.