In a reproduction apparatus, for reproducing an original signal conveyed as main data by a data medium such as a recording disk or broadcasting system, with medium protection data which are specific to the data medium being conveyed together with the main data, the apparatus includes a section for generating...http://www.google.com/patents/US6876700?utm_source=gb-gplus-sharePatent US6876700 - METHOD FOR PROTECTION OF DATA DECODING ACCORDING TO TRANSFERRED PROTECTION DATA, FIRST AND SECOND APPARATUS PROTECTION DATA AND A FILM CLASSIFICATION SYSTEM, TO DETERMINE WHETHER MAIN DATA ARE DECODED IN THEIR ENTIRETY, PARTIALLY, OR NOT AT ALL AND A RANGE OF PROTECTION LEVEL THEREFOR
