A METHOD OF PROVIDING SECURITY MARK WITH OVERT AND COVERT SECURITY FEATURE�

摘要

A multi-layered security mark with robust security features comprising of a substrate; a color changing overt layer as visible layer or calligraphy, superimposed over the substrate; and a machine generated dynamic hidden covert layer, superimposed over the overt layer; wherein, wavelength used to excite the ink falls in visible range; security feature is visible under normal lighting condition which eases the end user to locate the feature position for authentication; and security features are prominently visible when printed on black surface which appears as solid C=0, M=0, Y=0, K=100 color to the naked eye. Further, the invention also provides a customized device for authenticating the mark. Figure 4 on Sheet 3 of the drawings may accompany the abstract when published.