A biometric system is generally a pattern recognition system which makes a personal identification by determining the authenticity of a specific physiological or behavioral characteristic indigenous from the user. Unimodel biometric systems perform person recognition based on a single source of biometric information and are affected by problems like noisy sensor data, non-universality and lack of individuality of the chosen biometric trait, absence of an invariant representation for the biometric trait and susceptibility to circumvention. Some of these problems can be alleviated by using...