The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 01, 2008
Filed:
Jun. 10, 2002
Stanley T. Chow, Nepean, CA;
Harold J. Johnson, Nepean, CA;
Stanley T. Chow, Nepean, CA;
Harold J. Johnson, Nepean, CA;
Cloakware Corporation, Ottawa, Ontario, CA;
Abstract
Digital marks (so-called fingerprints and watermarks) serve two basic purposes: (1) Investigative: the owner reads a fingerprint to determine how the marked entity leaked; and (2) Legal: the owner must prove in court that (a) there is a watermark (a concealed copyright message), and (b) it is the owner's. The main difficulty of item (2) is that the first use of the watermark software reveals the watermarking method to the public so that hostile parties are equipped to remove or damage its watermarks. The invention uses tamper-resistant software encoding techniques to protect the digital mark extractor algorithm, frustrating the attacks of hostile parties in two ways: the resulting code is obscure (that is, its inner workings are incomprehensible; and chaotic (that is, a modification at any point will almost certainly produce a nonsense program.