This Small Business Innovation Research Phase I project is intended to develop a covert system of a customized pattern of the starting image that is invisible to the eye and a detection instrument that will display the image upon appropriate interrogation for authentication. Decryption will require the simultaneous viewing of two templates. The covert images for the templates will be created from Computer Generated Holograms (CGHs) that use inverse functions like Fourier transformations and thereby code the original image. The information of each of the complementary files will be embedded as transparent nanostructures by either using nano- or femto- second laser ablation technology or maskless photolithography with a Digital Micromirror Device (DMD) modified to act as a Spatial Light Modulator. The original image will be revealed upon appropriate juxtaposition of both complementary pieces simultaneously with projected light from an appropriate decoding instrument.<br/><br/>The unauthorized copying and theft through the counterfeit manufacture of copyrighted materials, brand name, trademarked property, credit cards and even individual identities is one of the greatest concerns of both businesses and individuals today. Today 95 percent of the ID industry (military, commercial, industrial, private and government offices) relies on portrait ID cards as their primary means of access control. The proposed ID authentication system aims to supplement the security aspects of such ID cards by embedding covert signatures, representing biometric and/or other identification features, onto current plastic ID cards.