Abstract: Method for addressing at least one service in a data communication system comprises at least one data transmission network (6, 12a, 12b, 15a, 15b, 16, 17) for transmitting information in at least one preferably MPEG data transmission stream (TS). In the method one or several service_providers transmits services to one or several data transmission networks (6, 12a, 12b, 15a, 15b, 16, 17). The service is assigned an identification (original_network_id, transport_stream_id, service_id), wherein on basis of the identification (original_network_id, transport_stream_id, service_id), it is possible to retrieve the data transmission stream (TS) to be used and the location in the data transmission stream (TS). The service is assigned an identifying name (service_provider_name, service_name) and a relation between the name information and the identification data, wherein on the basis of the name information (service_provider_name, service_name) and the relation, it is possible to retrieve the service identification.

Abstract: A personal trusted device is capable of communicating with a rendering machine such as an audio amplifier. Content to be played on the amplifier is selected by a user of the personal trusted device, the relevant permissions being negotiated between the device and the machine. Thus, it is possible for encrypted digital content to be rendered at a location and on a machine suited to the user's requirements.