Biometric Recognition: An Overview

Human identifi cation leads to mutual trust that is essential for the proper functioning of society. We have been identifying fellow humans based on their voice, appearance, or gait for thousands of years. However, a systematic and scientifi c basis for human identifi cation started in the nineteenth century when Alphonse Bertillon (Rhodes and Henry 1956 ) introduced the use of a number of anthropomorphic measurements to identify habitual criminals. The Bertillon system was short-lived: soon after its introduction, the distinctiveness of human fi ngerprints was established. Since the early 1900s, fi ngerprints have been an accepted method in forensic investigations to identify suspects and repeat criminals. Now, virtually all law enforcement agencies worldwide use Automatic Fingerprint Identifi cation Systems (AFIS). With growing concerns about terrorist activities, security breaches, and fi nancial fraud, other physiological and behavioral human characteristics have been used for person identifi cation. These distinctive characteristics, or biometric traits, include features such as face, iris, palmprint, and voice. Biometrics (Jain et al. 2006, 2007 ) is now a mature technology that is widely used in a variety of applications ranging from border crossings (e.g., the US-VISIT program) to visiting Walt Disney Parks.