Patent ID: 8037310

Claim:
A method for authenticating a first document by an authentication device, the first document comprising a visual representation of content and a first digital fingerprint, the method comprising: associating the first document with at least one auxiliary document, the visual representation of content of the first document including at least a portion of the at least one auxiliary document; reading the first document to obtain the first digital fingerprint and an indicator of a storage location for the content; determining the storage location for the content based on the indicator; retrieving content stored at the determined storage location; outputting, for visual verification by a human, the first document with the first digital fingerprint and a human-readable tag identifying an entity associated with the first digital fingerprint; verifying the first digital fingerprint; generating authentication indicia for the first document, the authentication indicia comprising a representation of at least a portion of the retrieved content and providing an assertion that the authentication device has authenticated the first document and the content has not been modified; and outputting a new version of the first document having a footer comprising the authentication indicia.