Identity authentication systems and techniques are disclosed which solves the problem associated with limited processing power and smart card technology in the handling of biometric authentication. By distributing the processing of an identity authenticating process between a smart card and a computer terminal, the complicated calculation involved in a biometrics matching process can be carried out to allow verification using biometric parameters stored on smart cards. There is disclosed a system and technique for user authentication, together with a system and technique for distributed processing. A registration method is also described.