INFORMATION RECORDING DEVICE, INFORMATION REPRODUCING DEVICE, ENCRYPTION PROCESSING KEY REVISION METHOD, AND PROGRAM PROVIDING MEDIUM

摘要

PROBLEM TO BE SOLVED: To provide an information recording and reproducing device and its method that selectively use a key revision block(KRB) of the newest version so as to encrypt contents and store them to a recording medium. SOLUTION: Keys with different versions can be stored on a recording medium, and when a recording and reproducing device accesses the recording medium, the processing of detecting a new key and storing it to the recording medium, the processing of storing the newest KRB detected from the recording medium to a memory of the recording and reproducing device itself, and the processing of deleting unnecessary KRBs from the recording medium are executed. The recording and reproducing device having a KRB newer than the KRBs in the recording medium records the new KRB to the recording medium even when no data are recorded. Through the configuration above, the migration speed of the new KRB is increased and new KRBs are stored one after another to the recording and reproducing device so as to promote revision of the KRB used for the encryption processing.