Abstract: Identifying attackers is a major apprehension to both organizations as well as governments. The most used applications for prevention or detection of intrusion are based on biometric systems. Biometrics is inherently most reliable and most capable than any other traditional knowledge-based and token-based techniques. The bio stands for life and metric stands for measurement, combined together make the term "biometrics". Biometric recognition refers to an automatic recognition of individuals by determining the authenticity of a specific physiological or behavioural characteristic based on feature vector possessed by the user. The biometric authentication provides the instances of authentication in such a quick and easy manner that individuals are not bothered by the additional requirements. It is a promise of fast, easy-to-use, accurate, reliable, and less expensive authentication for a variety of applications. This paper provides an overview of the different biometric techniques with their respective inherent features.

Keywords: Biometrics, eigenfaces, principal component analysis, signature dynamics.