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:
Jan. 23, 2001
Filed:
Jan. 28, 1998
Yossef Tsuria, Shoham, IL;
NDS Limited, , GB;
Abstract
A system for producing an output scrambled digital data stream from an input scrambled digital data stream. The input scrambled digital data stream includes a plurality of control messages (ECMs), each ECM including coded information for generating a control word (CW) associated with the ECM and being encoded using an ECM key. The input scrambled digital data stream also includes a plurality of segments of scrambled digital data, each segment of scrambled digital data being associated with one of the plurality of ECMs and being scrambled using the CW associated with the ECM. A method for producing the output scrambled digital data stream includes replacing each of the plurality of ECMs with a corresponding transformed ECM (TECM), each corresponding TECM comprising coded information for generating the CW associated with the corresponding ECM and being encoded using a TECM key, thus producing the output scrambled digital data stream, wherein the ECM key is replaced with a new ECM key at an ECM key change time, and the TECM key is not replaced at the ECM key change time.