Method and multimedia unit for processing a digital broadcast transport stream

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

• generating, by the multimedia device or by the security module, a selection command, the selection command indicating that the conditional access messages have to be sent to the security module when a connection to the server is not available or is not adequate, and the selection command indicating that the conditional access messages have to be sent to the server when a connection to the security module is not available;
• sending said conditional access messages from the multimedia device to the server through said return path or to the security module depending on said selection command;
• verifying the authentication of the multimedia device and/or the validity of access rights allocated to said multimedia device 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 device, said control data corresponding to said conditional access messages;
• and
• descrambling said audio/video/data content packets using said control data at the multimedia device.