| NAGRA FRANCE SAS Patent applications |
| Patent application number | Title | Published |
|---|
| 20110293092 | SECURITY METHOD FOR PREVENTING THE UNAUTHORIZED USE OF MULTIMEDIA CONTENTS - A method embeds tracing secret data into multimedia contents delivered to particular users. The method descrambles a first scrambled video stream having alternate values to obtain a personalized video stream corresponding to an original video stream by a decoder comprising at least a security unit and a descrambling unit, the personalized video stream being obtained by restoring the alternate values by personalized values taking into account an internal parameter on the security unit and received control data containing the original values and their location in the modified stream. | 12-01-2011 |
| 20100208891 | METHOD AND SYSTEM FOR THE SECURE DISTRIBUTION OF AUDIOVISUAL DATA BY TRANSACTIONAL MARKING - A process for distributing a marked audiovisual sequence from a nominal audiovisual sequence towards a receiver, said nominal audiovisual sequence having a nominal content, comprising: generating a marked audiovisual sequence according to a first mark applied to initial content at marking positions; generating a modified stream having a modified content different from the nominal content at least at marking positions; generating a complementary stream so that it is possible to reconstitute the marked audiovisual sequence from the modified stream; and transmitting the modified stream and the complementary stream towards the receiver wherein, on the receiver, a reconstitution of the audiovisual sequence, comprises calculating new complementary data according to the marking positions and the complementary stream so that it is possible to create an audiovisual sequence marked with a second mark from the modified stream, wherein the second mark, being different from the first mark, is applied to the initial content at the marking position. | 08-19-2010 |
| 20090202072 | CONTROL MESSAGE PROCESSING METHOD - This invention relates to a method for processing control messages from a set of control messages intended to access an encrypted content received in the form of a stream by a multimedia unit. These messages include at least a discrimination parameter having a different value for two consecutive messages in the stream and access data to encrypted content. The method comprises steps for receiving a current control message, for reading the discrimination parameter from the current control message, for retrieving in a memory, the discrimination parameter from the message processed previously to the current message, for comparing the discrimination parameter of the current message with the previously processed message discrimination parameter, and for blocking said current control message by the filter if the comparison step indicates that the discrimination parameter of the current message is identical to the discrimination parameter of the previously processed message. | 08-13-2009 |
