Biometric Systems for User Authentication

Authenticating the identity of users is a critical issue in information security. Biometrics is known for recognizing users based on their physiological or behavioral traits as identifiers and these cannot be easily stolen unlike passwords or ID cards. Biometrics could be employed as the primary means for authentication, called user identification, as well as a complementary (secondary) method for authentication, known as user verification. Biometric traits that cannot be easily forged and are supposedly unique for each user can form the basis of techniques for user identification. Biometric traits that need not be unique for each user; but, can be used to validate whether a user is whom he/she claims to be form the basis for user verification techniques. The first half of the paper describes several biometric techniques used for identification and verification and compares them with respect to different operating parameters. In addition, the different components (constituent blocks) of a biometric system and the performance metrics used to analyze the effectiveness of biometric systems are also discussed. The second half of the paper focuses on the security aspects of biometric systems, especially spoofing attacks and a solution to enhance the security and effectiveness through multibiometric systems.