A data processing device having a data processing unit for processing stream data composed of a plurality of frames generated with encoded contents data, the data processing device comprising: a protected storage unit for storing data, the protected storage unit being provided inside an integrated circuit to be protected from external access from outside said integrated circuit; a non-protected storage unit for storing data, the non-protected storage unit being provided external to the integrated circuit to be accessible from the outside; characterised by further comprising: a receiving unit for receiving contents data in a encrypted stream and further, index information for special reproduction of the stream, wherein the stream data includes a plurality of data pieces and the index information is external to the encrypted stream data and indicates positions of first data pieces being ones of the data pieces that store frames necessary for special reproduction of the contents; a decrypting unit for decrypting the encrypted stream data to acquire the stream data; a separating unit for separating, based on the index information, the data pieces included in the stream data into the first data pieces, and second data pieces that do not store frames necessary for special reproduction, and for storing the first data pieces in the protected storage unit, and for storing the second data pieces in the non-protected storage unit; and an output unit for outputting one data piece at a time, according to an order in which first data pieces and second data pieces are included in the stream data. a protected storage unit for storing data, the protected storage unit being provided inside an integrated circuit to be protected from external access from outside said integrated circuit; a non-protected storage unit for storing data, the non-protected storage unit being provided external to the integrated circuit to be accessible from the outside; characterised by further comprising: a receiving unit for receiving contents data in a encrypted stream and further, index information for special reproduction of the stream, wherein the stream data includes a plurality of data pieces and the index information is external to the encrypted stream data and indicates positions of first data pieces being ones of the data pieces that store frames necessary for special reproduction of the contents; a decrypting unit for decrypting the encrypted stream data to acquire the stream data; a separating unit for separating, based on the index information, the data pieces included in the stream data into the first data pieces, and second data pieces that do not store frames necessary for special reproduction, and for storing the first data pieces in the protected storage unit, and for storing the second data pieces in the non-protected storage unit; and an output unit for outputting one data piece at a time, according to an order in which first data pieces and second data pieces are included in the stream data. a receiving unit for receiving contents data in a encrypted stream and further, index information for special reproduction of the stream, wherein the stream data includes a plurality of data pieces and the index information is external to the encrypted stream data and indicates positions of first data pieces being ones of the data pieces that store frames necessary for special reproduction of the contents; a decrypting unit for decrypting the encrypted stream data to acquire the stream data; a separating unit for separating, based on the index information, the data pieces included in the stream data into the first data pieces, and second data pieces that do not store frames necessary for special reproduction, and for storing the first data pieces in the protected storage unit, and for storing the second data pieces in the non-protected storage unit; and an output unit for outputting one data piece at a time, according to an order in which first data pieces and second data pieces are included in the stream data.