With the pioneering studies of Galton and Henry on ?ngerprint-based human id- ti?cation over a hundred years ago, biometrics recognition is now permeating many sectors of our society. Even though the origins and the most frequent use of b- metrics, primarily ?ngerprints, have been in forensics and law enforcement app- cations, biometric recognition is now needed to address a number of societal pr- lems related to security risks, terror threats and ?nancial fraud. In some situations, for example, detecting duplicate enrolments (for issuing of?cial documents such as passports and driver...