While issues of encryption, firewalls, surveillance technologies, and cyber terrorism occupy the day-to- day thoughts of contemporary practitioners on the frontiers of information science, the essential problems they face are old, not new. The concept of document security goes back to some of the earliest eras from which writing survives. Testimony to the efforts of information professionals confronting security issues in the ancient world can be found in business, government, family, and temple contexts.
A Perceptual Image Hashing Algorithm for Hybrid Document Security