Model change device

摘要

A model change device replaces a first record/playback device with a second record/playback device due to change in a contract between a user and a service provider, the first record/playback device being usable under the contract. The first and second record playback device each include: an internal storage unit operable to store a content that is a digital work, a unique information storage unit operable to prestore device unique information that is unique to the respective record/playback device, an encryption unit operable to encrypt the content stored in the internal storage unit based on the device unique information stored in the unique information storage unit to generate encrypted information, a write unit operable to write the generated encrypted information into a storage area of a recording medium device, a read unit operable to read the encrypted information from the storage area of the recording medium device, a decryption unit operable to decrypt the read encrypted information based on the device unique information stored in the unique information storage unit to generate a decrypted content and a playback unit operable to play back the generated decrypted content.

The model change device includes a read unit operable to read the device unique information stored in the unique information storage unit of the first record/playback device and delete the device unique information from that unique information storage unit and a write unit operable to write the read device unique information into the unique information storage unit of the second record/playback device.