Synopsis Something you have - A key or a token; something you know ? A password or a PIN; and something you are – Biometric.Biometrics is a method of identification and verification based on individual physical traits. Thus, one’s fingerprints, one’s face, one’s iris can all be biometric identifiers. Why Biometrics? Because, unlike a key or a token, a biometric identifier cannot be stolen or lost; it remains with an individual. Unlike a password or a PIN, it cannot be forgotten or hacked. It is an integral part of one’s biological make-up.Awareness and interest in biometric technologies increased after 9/11. Western countries were quick to enact legislation and install biometric systems at national borders and other sensitive areas. This frenzy in biometric installations made some individuals and groups uneasy. They were concerned about violation of privacy and possible misuse of biometrics. Besides applications in purely national security, biometric technologies are being used in other areas, too; for example, in payment systems and ATMs. The financial sector is embracing biometric technology enthusiastically. In India, the leading national and foreign banks are experimenting with biometric ATMs. The first section of this book describes the basics of biometric technology. It covers various technologies and then discusses the challenges in large-scale implementation of biometric identification techniques. The second section describes the applications of technology in such diverse fields as border security, passport, airport security, law enforcement, banks, payment system and ATMs. Because of the growing concerns over security and the promise biometric technology holds, it will soon become all pervasive.