Five years have experienced significant growth in biometric research resulting in the development of innovative sensors, robust and efficient algorithms for feature extraction and matching, enhanced test methodologies and new applications. These advances have resulted in a strong, accurate, secure and cost effective biometric systems. Handbook of Biometrics - edited volume contributed by prominent invited researchers in Biometrics - describes the fundamentals and recent advances in the thriving field of biometrics. It is designed for professionals consisting of practitioners and researchers in Biometrics, Pattern Recognition and Computer Security. Handbook of Biometrics can be used as the primary text for undergraduate classes biometrics.