Reproduction device and program

A playback apparatus that plays back video data, with use of basic information for controlling playback of the video data, from a first recording medium on which the video data and the basic information are recorded, the playback apparatus comprising:

• an interface in which a second recording medium can be inserted and from which the second recording medium can be removed;
• a detection unit operable to detect that the second recording medium is inserted in the interface;
• and
• a playback control unit operable to control playback of the video data, wherein if the detection unit detects that the second recording medium is inserted in the interface during playback of the video data recorded on the first recording medium, and furthermore if supplementary information for controlling playback of the video data is recorded on the second recording medium, the playback control unit judges whether the supplementary information is associated with the basic information,
• if the supplementary information is judged to be associated with the basic information, the playback control unit changes an attribute of the supplementary information to read-only, and performs signature verification on the supplementary information with use of certificate data recorded on the first recording medium and signature information recorded on the second recording medium, and
• if the supplementary information is judged to be authentic as a result of the signature verification, after stopping playback of the video data with use of the basic information, the playback control unit performs control to play back the video data with use of the basic information on the first recording medium and the supplementary information on the second recording medium.

A control program executed in a playback apparatus that plays back video data with use of basic information for controlling playback of the video data, the playback apparatus including a CPU, an interface in which a second recording medium can be inserted and from which the second recording medium can be removed, and a detection unit operable to detect that the second recording medium is inserted in the interface, from a first recording medium on which the video data and the basic information are recorded, the control program comprising:

• a playback control step, wherein
• if the detection unit detects that the second recording medium is inserted in the interface during playback of the video data recorded on the first recording medium, and supplementary information for controlling playback of the video data has been recorded on the second recording medium, a judgment is made whether the supplementary information is associated with the basic information,
• if the supplementary information is judged to be associated with the basic information, an attribute of the supplementary information is changed to read-only, signature verification of the supplementary information is performed with use of certificate data recorded on the first recording medium and signature information recorded on the second recording medium, and
• if the supplementary information is judged to be authentic as a result of the signature verification, after stopping playback of the video data with use of the basic information, control is performed to play back the video data with use of the basic information on the first recording medium and the supplementary information on the second recording medium.