Digital Watermarks and Palimpsest Steganography in Special Collections

摘要

Libraries today face the same challenges that they always have faced, but with the additional dimension that the world of computers engenders. Policies and practices have been developed for deterring theft and for recovering stolen library materials in the analog world, but we are in an incunabula period for doing the same for digital documents-images and pictorial and sound materials. One means of protection for both kinds of materials is marking them indelibly. This can be done in a variety of ways for physical materials, but there is a new world of electronic marking that is in its infancy. This practice, called Steganography, creates digital watermarks that can be hidden, but they may also be detected and erased. This essay discusses attempts to create digital watermarks that resist tampering with.