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:
Feb. 17, 2015
Filed:
Mar. 01, 2010
Philip Allan Eisen, Ottawa, CA;
Ettore Benedetti, Leiden, NL;
Arnoud Evert Van Foreest, Leiden, NL;
Andrew Augustine Wajs, Haarlem, NL;
Philip Allan Eisen, Ottawa, CA;
Ettore Benedetti, Leiden, NL;
Arnoud Evert Van Foreest, Leiden, NL;
Andrew Augustine Wajs, Haarlem, NL;
Irdeto B.V., Hoofddorp, NL;
Abstract
Embodiments of the invention provide an improved method and an improved receiver for obtaining a control word. Two or more subkeys are obtained in a receiver. Each subkey was encrypted under control of a key received in an entitlement message or transformed under control of a seed received in an entitlement message. After decryption or transformation, the subkeys are combined to obtain the control word. Typically at least one of the entitlement messages is a positive entitlement message and at least one of the entitlement messages is a negative entitlement message. Embodiments of the invention can be used in a conditional access system such as a Pay-TV system.