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:
Dec. 23, 2008
Filed:
May. 09, 2003
David Jay Duffield, Indianapolis, IN (US);
Mark Alan Schulz, Indianapolis, IN (US);
Michael Scott Deiss, Indianapolis, IN (US);
David Jay Duffield, Indianapolis, IN (US);
Mark Alan Schulz, Indianapolis, IN (US);
Michael Scott Deiss, Indianapolis, IN (US);
Thomson Licensing, Boulogne Billancourt, FR;
Abstract
A method for protecting the digital output signal of a security module, comprising the steps of: receiving a scrambled digital signal from a source external to said security module, recovering at least one transport scramble control flag from the scrambled digital signal, descrambling said received scrambled signal to generate a descrambled signal, monitoring the at least one transport scramble control flag, generating a scrambling key in response to said monitored at least one transport scramble control flag, and scrambling said descrambled signal using said scrambling key to generate a re-scrambled signal. The present invention also includes a conditional access system comprising a host device and a security device coupled to the host device, such that the security device includes at least one transport scramble control flag modification circuit. By monitoring the transport scramble control flag as content passes through the security module, protection of the content can be securely maintained.