Abstract: The invention is related to authenticating records, which include images, video and sound recordings, preferably in digital form, of people, pets, events, places, physical objects, processes and methods, services, documents, drawings and artwork. Authentication comprises determining and recording the record's attributes and the record-owner's identifying information, by an independent certifying authority, appending the determinations and attesting the certifier's seal, with date and location stamps, to the original record. More robust authentication entails maintaining the entire augmented record on a secure server in read-only format if requested by the record-owner. Also, if requested by the record-owner, the entire certified record is made accessible to third parties.

Abstract: A simple method and an inexpensive portable device to enter expressions in which the expressions can be linked and automatically updated at all links whenever one particular instance of the linked expression is revised; and, the results, for the mathematical expressions, are automatically re-computed, updated, saved and auto-displayed.