Verschluesselung und Entschluesselung von Multimediadaten

The encoding method involves using a coding index (34,36,38,44,46) which is entered in the specification information block (30) for the multi-media data. This is used for subsequent coding of at least part of the multimedia data block, using a coding algorithm selected from a number of coding algorithms. The specification information block contains a release index (42), identified by a decoding device, for decoding the coded multimedia data. The size of the multimedia data block to be coded via the coding algorithm can be specified via a quantity index (32). USE - For preventing unauthorised access to multimedia data, such as television channels.