Biometric authentication methods use biometric characteristics or traits to verify users’ claimed identities when users access endpoint devices, networks, networked applications or Web applications. Across a wide range of use cases, any biometric authentication method may be used in one-to-one comparison mode (when the user enters a user ID), or one-to-many search mode (when the user simply presents his or her biometric characteristic, with no explicit claim of identity, and the system determines his or her user ID from a range of candidates).