INTELLIGENT BROADCASTING SYSTEM FOR SUPPLYING A MULTI-QUALITY SERVICE, PARTICULARLY WITH REGARDS TO SUPPLYING ONE BROADCASTING CONTENT WITH MORE THAN TWO QUALITIES

PURPOSE: An intelligent broadcasting system for supplying a multi-quality service is provided to employ an encryption key and a demultiplexing control policy in complex way, thereby effectively cutting off an access to a service quality which is not approved at data receiver level. CONSTITUTION: A broadcasting device(210) comprises as follows. Multi-level encoders(211,212) encode one source data at multi-level, and generate plural multi-level encoding data. A multiplexer(214) multiplexes the encoding data, and generates multiplexing data. An encoder(215) encodes the multiplexing data, and generates encoding data. A transmitter(216) broadcasts the encoding data. A broadcast receiving device comprises as follows. A receiver receives the encoding data. An encryption decoder decodes the encoding data, and generates the multiplexing data. A demultiplexer demultiplexes the multiplexing data, and generates the multi-level encoding data. A multi-level decoder decodes the encoding data. An access quality control system permits the source data to be reproduced with more than one of receiving qualities associated with the one of the source data.