Nagravision S.a.

Philippe Desarzens

Fabien Gremaud

Jean-Luc Bussy

Henri Kudelski

Frederic Thomas

Guy Moreillon

Thierry Dagaeff

Sebastien Robyr

Sébastien Robyr

The present invention relates to a system for rendering a content, the rendering of which is subject to conditional access security conditions. A system is described, comprising a host device and a detachable security device, the security device configured to decrypt the encrypted content, re-encrypt it under a local key and to deliver the re-encrypted content to the host device while ensuring that the host device applies or otherwise enforces any conditions associated with the rendering of the content.

System for decrypting and rendering content

A system for rendering a content, the rendering of which is subject to conditional access security conditions. The system includes a host device and a detachable security device, the security device configured to decrypt the encrypted content, re-encrypt it under a local key and to deliver the re-encrypted content to the host device while ensuring that the host device applies or otherwise enforces any conditions associated with the rendering of the content.

The present invention concerns a method for controlling the use of a conditional access content (C), said content being sent to a plurality of multimedia units (STB) connected to a management center (CG). The method comprises the steps of defining controlled content usage types; defining a set of usage rules (UR) for at least two controlled content usage types by setting condition values for these controlled content usage types; defining at least two content profiles (CP) by associating one usage rule of said at least two controlled content usage types; sending management messages containing the content profiles (CP) to at least a set of multimedia units (STB) linked to said management center; storing the content profiles (CP) in the concerned multimedia units; sending the conditional access content (C), and joined sending of a control message (ECM) containing at least a means for determining the content profile (CP) that is to be linked to the content (C); further to the reception by a multimedia unit of the encrypted content (C) and of the corresponding control message (ECM), extracting the means for determining the content profile that is to be linked to the content; searching in the multimedia unit, the content profile corresponding to the means for determining the content profile that is to be linked to the content; and of using the content (C) by the multimedia unit according to the usage rules contained in the content profile that is to be linked to the content. The invention further concerns a multimedia unit for implementing said method.

Method for controlling the use of a conditional access content and multimedia unit for implementing said method

A method allows a broadcasted conditional access content accessible at the time of transmission to be also accessible at a later time thanks to intermediate storage on a hard disk of a user unit. The processing method includes the steps of receiving at the user unit a data stream encrypted by at least one control word, at least one control message stream containing the control words, forming an index file, each index comprising an identifier of a control message formed by the extraction of data associated to the control messages and an identifier of the part of the content to which the control message is applied; and, at the time of the deferred processing of the content, extracting at least one part of the control messages and resynchronizing the content with the control messages by the use of the index file, the identifier of the control message allowing the selection of the current control message from a set of control messages at the time of the exploitation of the content identified by the identifier of the part of the content related to this control message.

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Bussigny, Switzerland

Philippe Desarzens