US Patent 8677132 Document security

A method for managing a secured document. The method includes storing and retrieving the secured document based on hybrid fragmentation and replication scheme to provide user viewing of the secured document by (a) generating an image representing human discernible content of the secured document, (b) modifying the image to generate a modified image that is embedded with a digital watermark, where the digital water mark is human indiscernible and represents a security policy extracted from the secured document, and (c) sending, to a secured device for displaying to the requesting user, the modified image embedded with the digital watermark.