9. The system of claim 4 , wherein said dialogue manager is adapted to employ a pass-phrase selection strategy that applies constraints to assembly of the multiple, selectable pass-phrases in a prompt presenting the multiple, selectable pass-phrases to the user during a single dialogue turn by applying the constraints to random selection of each pass-phrase in the prompt to ensure that the selection criteria assigned to each potential user identity are accommodated in the prompt in a distinguishable fashion complementing an analysis technique of said user identity analysis module.
4. A user authentication system, comprising: a dialogue manager, executed on a processor of the user authentication system, adapted to prompt a user with multiple pass-phrases and requests the user to select a proper subset from the prompted multiple pass-phrases during authentication, wherein the prompted multiple pass-phrases are formed by selecting one or more pass-phrases from a set of pass-phrases satisfying a rule associated with the user and selecting one or more pass-phrases that do not satisfy the rule associated with the user, where the rule associated with the user is determined prior to authentication and is not suggested to the user during authentication; a selection recognizer, executed on the processor of the user authentication system, receptive of at least one user selection input and adapted to recognize user selection of a proper subset of the prompted pass-phrases based on the user selection input; a user biometric matching module, executed on the processor of the user authentication system, receptive of a user biometric input and adapted to make a match based on biometrics of enrolled users; and a user identity analysis module, executed on the processor of the user authentication system, adapted to analyze at least one potential user identity based on the match between the pass-phrases in the proper subset and the rule associated with the user, wherein said dialogue manager is adapted to recursively prompt the user with new sets of multiple, selectable pass-phrases randomly assembled from a pass-phrase corpus over multiple dialogue turns, and said user identity analysis module is adapted to combine selection results and biometric match results from each dialogue turn to yield dialogue turn results and combine the dialogue turn results from each dialogue turn to form a cumulative result and authorize the user when the cumulative result exceeds a threshold.