Method and multimedia unit for processing a digital broadcast transport stream

A method for managing a processing of a digital broadcast transport stream received by a multimedia unit identified by a personal identifier, from a broadcaster through a wired or wireless network, said multimedia unit being connectable to a security module associated with the multimedia unit through a local secure connection, said multimedia unit being connectable to a server through an IP-connection provided with a return path, said transport stream comprising scrambled audio/video/data content packets and scrambled conditional access messages, said conditional access messages having to be processed to obtain control data necessary for descrambling said content packets, the method comprising the steps of:

• sending said conditional access messages from the multimedia unit to the server through said return path or to the security module depending on a selection command;
• verifying the authentication of the multimedia unit and/or the validity of access rights allocated to said multimedia unit and if said authentication fails or if said allocated rights are not valid, preventing any further processing of said conditional access message;
• securely obtaining, at the multimedia unit, said control data corresponding to said conditional access messages;
• and
• descrambling said audio/video/data content packets using said control data at the multimedia unit.