Abstract: An authentication system includes an object including an authentication hologram disposed over an area of a surface of the object. The authentication hologram is defined by a pattern of reflective material and includes latent authentication information. The system includes a computer-readable medium including program instructions for execution by one or more processors. The program instructions are executable by the one or more processors to: (i) receive, from an image capture device, a digital image of the authentication hologram, wherein light reflected by the reflective material is captured in the digital image of the authentication hologram, and (ii) detect the latent authentication information in the digital image of the authentication hologram, wherein an effect of the reflected light is reduced to detect the latent authentication information.

Abstract: An authentication system includes an object including an authentication hologram disposed over an area of a surface of the object. The authentication hologram is defined by a pattern of reflective material and includes latent authentication information. The system includes a computer-readable medium including program instructions for execution by one or more processors. The program instructions are executable by the one or more processors to: (i) receive, from an image capture device, a digital image of the authentication hologram, wherein light reflected by the reflective material is captured in the digital image of the authentication hologram, and (ii) detect the latent authentication information in the digital image of the authentication hologram, wherein an effect of the reflected light is reduced to detect the latent authentication information.

Abstract: A verifiable/copy-protected document features a combination of nearly identical line-screen patterns for embedding latent images within visually integrated settings. The latent images can be detected for purposes of verification with a matching viewer but are indistinguishable from their visually integrated settings under ordinary viewing conditions. The line-screen patterns, which can be incorporated into document artwork, are printed at certain combinations of line frequencies and print densities so that the line-screen patterns digitally reproduce as a largely undifferentiated solid tint.

Abstract: A compound security feature is formed by printing latent images together with visually integrated settings using an invisible ink. Even if illuminated by a wavelength capable of rendering the inks visible, the latent images remain visually indistinguishable from their visually integrated settings. However, the latent images and visually integrated settings differ in one or more less obvious ways so that the latent images can be distinguished by using a visual aid.

Abstract: A tamper and copy protected document includesn array of fine blind holes (or, alternatively, of fine perforations) impressed on the document in areas where specific information is to be imprinted. Imprinting of information on the array of holes (or perforations) results in penetration of ink into the fibrous interior of the document, between its surfaces. A resinous coating, applied over the array and over the imprinted information, also penetrates into the interior to encapsulate the ink. A copy protected document is produced by imprinting it with specific alphanumeric information which includes perforations in the imprinted characters.