The security field uses three different types of authentication: something you know, something you have, or something you are - a biometric. Common physical biometrics include fingerprints, hand geometry; and retina, iris, or facial characteristics. Behavioral characters include signature, voice. Ultimately, the technologies could find their strongest role as interwined and complementary pieces of a multifactor authentication system. In the future biometrics is seen playing a key role in enhancing security, residing in smart cards and supporting personalized Web e-commerce services. Personalization through person authentication is also very appealing in the consumer product area. In this lecture, we introduce the field of biometrics, classify the different biometrics and summarize the tradeoffs between accuracy and convenience. We give a special attention to the major biometrics (e.g. fingerprint, voice, face, iris and signature) and emphasize how these biometrics can be combined in practical systems. Finally, we focus on the performance and evaluation of these biometrics, the main application areas and several case studies
