A Study of Biometric, Multimodal Biometric Systems: Fusion Techniques, Applications and Challenges

Automatic person identification is an important task in our day- to-day life. The traditional method of establishing a person's identity include knowledge based like password or token based like ID cards, but representation of these identity can easily be lost, stolen or shared. Therefore they are not sufficient for identity verification.Therefore biometric systems are used to overcome the limitations of traditional methods. The survey of biometric and multimodal biometric systems is therefore necessary for high security applications. This paper discusses the biometric system, an overview of multimodal biometrics, challenges in the progress of multimodal biometrics, and its applications to develop the security system for high security areas. Identity management system is challenging task in providing authorized user with secure and easy access to information and services across a wide verity of networked system. A reliable identity management is a critical component in several applications that provide services to only legitimately enrolled users. Some of applications include physical access control to secure facility, access to computer networks, performing remote financial transactions etc. The primary task in an identity management system is determination of individual's identity. This action may necessary for many reasons but in most applications, primary intention is to prevent imposters from accessing protected resources. The traditional method of establishing a person's identity include knowledge based like password or token based like ID cards, but these representations of the identity can easily be lost, stolen or shared. Therefore they are not sufficient for identity erification. Biometric offers natural and reliable solution to the problem of identity determination by recognizing individuals by using certain physiological or behavioral traits associated with the persons. Biometrics is the science of identifying or verifying the identity of person based on physiological or behavioral characteristics (1). Physiological traits are related to physiology of the body and mainly include fingerprint, face, ear, iris, retina, hand, palm geometry. Behavioral traits related to the person such as signature, voice etc. However, a single biometric characteristic sometimes fails to be accurate enough for the identification because it may suffer a variety of problems such as noisy data, non-university, within-class variation, between-class similarity and spoof attacks (2-4). One of the methods to overcome these problems is to make use of multimodal biometric authentication systems, which combine information from multiple modalities to arrive at a decision. Studies have demonstrated that multimodal biometric systems can achieve better performance compared with unimodal systems. The paper is organised as follows. A typical biometric system is discussed in Section II, where as need of multimodal biometrics is illustrated in Section III. Multimodal biometric system and different fusion techniques are presented in Section IV. Applications in section V, challenges in Section VI and conclusions are presented in the last section of the paper.