INTRODUCTION

Remember , Tom cruise having from a rope upside down in mission impossible trying to gain access into a send alone computer of CIA in a black, heat insulating suit and constantly monitoring his body temperature to prevent registering an increase in the preset room temperature, so that thermal radiation measurement devices don’t give away the intrusion?

Any Hollywood action movie these days typically include high-tech gizmos installed for restricting physical access, the likes of which could be seen in Mission Impossible. Prominent among these are high security authentication systems, a manifestation of which can be seen in establishments having access restrictions. In such situations, access is usually granted by a device, which takes into account some physical parameter of the person seeking access or entry, e.g. his fingerprint, eye or face and allows access only when there is a match with a previously existing sample of the same parameter.

Biometrics is the science and technology of measuring and statistically analyzing biological data. Biometric technology is defined as automated methods of identifying or authenticating the identity of a living person based on a physiological of behavioral characteristic. Some examples include measures based on information from handwriting, fingerprints, face, voice, retina, iris, hand, ear shape and gait data.

A biometric system is a pattern recognition system that establishes authenticity of a specific physiological or behavioral characteristic possessed by the user. The ability of monomodal system to reject imposters, who claim a false identity, becomes a critical issue in security applications.

A single feature sometimes fails to be exact enough for identification; for example, in case of identical twins their faces alone may not distinguish them. Other disadvantage of using only one feature is