Patent ID: 7599513

Claim:
A device which encodes and marks documents for identification and retrieval, which device collects sequential pixel information during scanning or during printing of a document, and which device further comprises: a conversion mechanism that transforms this sequential information into a code A which has a one-to-one relationship to the sequential pixel information; and a computational mechanism that computes from this code A and physical information B collected during the actual printing or scanning process from mechanical movement and electronic circuitry of a printer or scanning device, a hashcode H which meets the requirements of a digital signature, and a means which then feeds the digital information needed to print the hashcode H to the printer, in a pixel format as a part of a printed document page, wherein the device further includes at least two buffers which provide the signals for forwarding the computed hashcode H to a Hardware Hash to Pixelcode Converter, and for forwarding the hashcode pixel data via a Hardware Timing Unit to be incorporated into the document which is printed.