the presently claimed invention relates generally to gaining access to secure systems . one claim recites an apparatus including : an image or video sensor for capturing image or video data ; and a multi - purpose computer processor configured to : decode machine - readable information encoded in captured image or video data representing a plurality of physical objects , each instance of machine - readable information includes identifying information ; determine an order in which the physical objects are presented to the image or video sensor for evaluation via the identifying information ; and comparing the order to a predetermined sequence to determine whether to allow access to a remotely located computerized system . the apparatus may be housed , e . g ., in a cell phone . other combinations and claims are provided as well .