Patent US 8,355,993

A method and system for authenticating an end user. A first pattern of colored quadrilaterals is generated. A second pattern of multiple colored nodes that include a first subset of nodes is generated. The first and second patterns are sent to the end user. If a transparent credit card is overlaid by the end user on top of the second pattern, then a second subset of nodes in the credit card would match in color and location the first subset of nodes. The authenticity status of the end user is determined by determining whether each node of a third subset of nodes within the second subset of nodes (i) corresponds to a unique node of the multiple colored nodes and (ii) has a color that matches a specific color in one quadrilateral of the colored quadrilaterals. The determined authenticity status is sent to the end user via an output device.