A data reproducing apparatus high in security against unauthorized duplication. A drive 20 includes a first CSS encoder 21 for performing first encryption processing on picture data etc reproduced from an optical disc D and a second CSS encoder 22 for performing second encryption processing different from the first encryption processing on the media type information of the optical disc D. The drive transmits the so-processed data or information. A data processing device 30 performs decryption processing on the transmitted picture data etc and on the media type information by respective independent decoders. The data processing apparatus detects the copyright control information from the picture data etc and performs reproduction limitation or recording limitation on the picture data etc.