Patent Number: 8,578,177

Title: Recording device, and content-data playback system

Abstract: A recording device configured to store content data in an encrypted manner, the recording device comprises a memory unit which stores various data, and a controller which controls the memory unit. The controller possesses a controller key and unique identification information, and is configured to generate a controller-unique key unique for each controller in accordance with the controller key and the identification information. The memory unit stores an MKB generated by encrypting a medium key with a device key set that is a collection of a plurality of device keys, an encrypted device key set generated by encrypting the device key set with the controller-unique key, and a device-key-set index which uniquely identifies the device key set. The controller comprises a decryption unit which obtains a device key set by decrypting the encrypted device key set with the controller-unique key, an ID generating unit which generates a medium ID from the identification information and the device-key-set index, and an authentication unit which executes an authentication process with an exterior in accordance with the device key set, the medium ID and the MKB.

Inventors: Matsukawa; Shinichi (Suginami-ku, JP), Kato; Taku (Kamakura, JP), Kasahara; Akihiro (Sanbu-gun, JP), Suu; Hiroshi (Chigasaki, JP), Kondo; Atsushi (Yokohama, JP), Sato; Jun (Kokubunji, JP), Miura; Akira (Sagamihara, JP), Sakamoto; Hiroyuki (Ome, JP)

Assignee: Kabushiki Kaisha Toshiba

International Classification: G06F 12/14 (20060101)

Expiration Date: 1/05/12017