1. A biometric authentication system configured to enable an authentication process, the process having predefined parameters associated therewith, the process providing for authentication of a user based on a comparison of a presented biometric with at least one previously stored biometric, said authentication system comprising: a matching system providing as an output an output matching score based on the comparison of the presented and the at least one previously stored biometric, said authentication system being configured to authenticate the user on determining that a parameter based on the output matching score meets a threshold score, wherein the output matching score results from a combination of multiple output matching scores, or values transformed from the combination of multiple output matching scores, when compared against a single threshold score; and interrogation means configured to interrogate the authentication process so as to extract and use the predefined parameters to select an appropriate threshold score from a plurality of available threshold scores, each of the plurality of available threshold scores being previously generated for specific parameters.