Abstract: The invention concerns a method for providing a plurality of receivers with conditional access to broadcast services using a simplified means for managing the control messages required by such conditional access schemes. The method involves providing all information which will allow a registered receiver having the necessary decryption key to access the services without having any prior rights loaded locally. A management center keeps a register of all subscribed receivers, including a list of services to which the receiver is subscribed, and encrypts the services using control words encrypted by the necessary keys. Control messages comprising the control words for decryption are provided within a special channel to which the receiver has permanent access, the special channel being a different one from channels used for broadcasting audio/video services.

Abstract: A method of operating by a second processing unit a content recorded by a first processing unit, said first and second processing units having a specific key being managed by a central server. The processing units have access to a removable storage memory intended to record a content ciphered by a content key accompanied by a file associated to the content. The content key is produced by means of a cascaded deciphering starting from the specific key of the first unit of at least two constants provided by the central server and a variable. The content is restored by the second processing unit by means of a cascaded deciphering starting from the specific key of the second unit by using the constants and the variable stored in the file accompanying the content and a transcoding key calculated by the central server.

Abstract: 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.

Abstract: The present invention relates in particular to a method for processing multimedia content memorised in the form of digital data in at least one multimedia unit. This method includes the following steps: reception of a program map table containing at least one indication of a proprietary type of data associated to a packet identification data (PID) as well a flag; reception of a matching table between the flag value and the real type of data; search for the flag values appearing in the program map table PMT received by the multimedia unit; search for the corresponding flag values in the matching table between the flag value and the real type of data; and modification of the program map table by replacing the indication of the proprietary type of data of the program map table with the corresponding real type of data of the matching table. The invention furthermore concerns a method for sending multimedia content in the form of digital data, as well as a multimedia unit for implementing these methods.

Abstract: The invention concerns a method for accessing services by a user unit, said services being a subset of all services broadcast by a management center and comprising at least two services, said subset of services defining a package, each service being simultaneously broadcast and containing audio/video data, the data of a service being encrypted by at least one control word, the method comprising the steps of: determining in a management center, the package a user unit is entitled to access to; determining in said management center a unique key pertaining to said user unit; forming a message containing at least one control word for each service of the package for which the user's unit is entitled, said control word being secured by the key pertaining to said user unit so that said key must be used to obtain the control word; transmitting to at least said user unit said message on at least one channel accessible whatever the selected service is.

Abstract: A method of operating by a second processing unit a content recorded by a first processing unit, said first and second processing units having a specific key being managed by a central server. The processing units have access to a removable storage memory intended to record a content ciphered by a content key accompanied by a file associated to the content. The content key is produced by means of a cascaded deciphering starting from the specific key of the first unit of at least two constants provided by the central server and a variable. The content is restored by the second processing unit by means of a cascaded deciphering starting from the specific key of the second unit by using the constants and the variable stored in the file accompanying the content and a transcoding key calculated by the central server.

Abstract: 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.

Abstract: The present invention relates in particular to a method for processing multimedia content memorised in the form of digital data in at least one multimedia unit. This method includes the following steps: reception of a program map table containing at least one indication of a proprietary type of data associated to a packet identification data (PID) as well a flag; reception of a matching table between the flag value and the real type of data; search for the flag values appearing in the program map table PMT received by the multimedia unit; search for the corresponding flag values in the matching table between the flag value and the real type of data; and modification of the program map table by replacing the indication of the proprietary type of data of the program map table with the corresponding real type of data of the matching table. The invention furthermore concerns a method for sending multimedia content in the form of digital data, as well as a multimedia unit for implementing these methods.