Security document and authentication scheme

Abstract

A security document is provided including a unique combination of covert triggers, overt triggers, and overt secure document indicators arranged to enhance the security of the document at issue. In accordance with one embodiment of the present invention, a security document is provided including a security image and a covert trigger printed on a face of the document. The security image is defined by a collection of security image elements. The security image defines at least one document authentication scheme. The document authentication scheme is arranged to provide an indication of document authenticity. The covert trigger is defined by a collection of trigger elements. The trigger elements are arranged to resemble the security image elements so the covert trigger is not readily apparent on the face of the document. In accordance with another embodiment of the present invention, a method of authenticating a security document is provided. The method includes the steps of:(i) defining an authentication constellation within the security image, wherein the authentication constellation defines a set of constellation pixels, and wherein the constellation pixels are arranged at predetermined coordinates within the security image; (ii) identifying respective occupation characteristics of each of the constellation pixels, wherein each of the respective occupation characteristics represents a degree of printed matter within a selected constellation pixel; and (iii) determining whether the respective identified occupation characteristics correspond to an authentic document by comparing the respective identified occupation characteristics to a set of authentic occupation characteristics.