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:
Nov. 24, 2009
Filed:
Oct. 12, 2004
Mark A. Hollar, Palo Alto, CA (US);
Mark A. Hollar, Palo Alto, CA (US);
Macrovision Corporation, Santa Clara, CA (US);
Abstract
Method and apparatus for inhibiting unauthorized copying of data content of DVDs or CDs or other types of optical discs. DSV (digital sum value) data patterns are inserted into selected sectors of the data to be recorded on the optical disc. These selected data sectors are also those to which is applied the conventional CSS (content scrambling system) encryption conventionally used to copy protect DVD content. Only those sectors (e.g., one out of four) subject to the CSS encryption have the DSV data patterns inserted therein. This advantageously results in the CSS encryption effectively hiding these inserted DSV data patterns from the mastering DVD encoder used in producing DVDs. Effectively thereby the DSV data patterns 'tunnel through' the mastering DVD encoder. The hidden DSV data patterns are only revealed when the CSS sectors are decrypted prior to the action of the writer used to copy the DVD/CD content. This results in those DSV data patterns being left in the clear at the writer so they are effective to result in an error-filled DVD data file which is not suitable for play back when recorded by the writer on another optical disc.