A system for testing faults in shadow logic includes a sequential block coupled to a shadow logic block and a delaying block to receive test patterns for testing the shadow logic block. The first jaw member has at least one row of fasteners arranged in a row substantially transverse to the longitudinal axis. This authentication credential includes a user identifier associated with a user and an address of a user device. The conductors of the elastic member are movable into contact with the contacts of the case member by an external force for moving the slide member away from the neutral position against a biasing force of the elastic member, and separable from the contacts by the biasing force of the elastic member when the external force is removed.