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:
Oct. 06, 2015
Filed:
Jan. 08, 2010
Jean-baptiste Henry, Melesse, FR;
Alain Durand, Rennes, FR;
Jean-Baptiste Henry, Melesse, FR;
Alain Durand, Rennes, FR;
Thomson Licensing, Issy-les-Moulineaux, FR;
Abstract
Delivery of conditional access data to a receiver that is able to connect to a plurality of scrambled programs. Conditional access for a current channel is handled using standard ECMs delivered with the channel. In parallel, the receiver retrieves an ECM for a separate stream comprising control words for every channel. The control word of this ECM is used to descramble the separate stream to access the control words for every channel. In a preferred embodiment, these control words are super-encrypted using channel keys and the receiver is only able to obtain channel keys for channels for which it has access rights. In case the control words are super-encrypted, they are decrypted. Upon channel change, the relevant retrieved control word is used to descramble the new channel. Also provided is a receiver device and a transmitter device. According to a variant, the control words received in the separate stream is treated only upon a change of channel. The invention enables a reduction or removal of the CA delay when switching between channels.