ENCRYPTION KEY INFORMATION HOLDING METHOD AND ENCRYPTION KEY INFORMATION PROCESSING APPARATUS

摘要

According to one embodiment, the amount of processing or the number of circuits needed to re-encrypt title keys is reduced, while keeping a strong protection of the title keys. An old protected area key Kpa0 and a new protected area key Kpa1 are held simultaneously in a memory of a key holding section. These old and new protected area keys Kpa0, Kpa1 are used to re-encrypt a title key file TKF.