Patent ID: 8312294

Claim:
An information processing apparatus to which a storage medium is connected, wherein the storage medium is configured to store title keys configured to encrypt a content, a first application key and a second application key configured to encrypt the title keys for each application of the content, a media key block, an authentication key, and a media unique key; the media key block comprises encrypted media keys encrypted by different device keys; the first application key and the second application key are encrypted by the media unique key; the media unique key is obtained from a media key and a media identifier; the information processing apparatus comprises: a calculation module configured to read the media key block from the storage medium and to obtain an authentication key from the encrypted media keys; an authentication module configured to read the authentication key from the storage medium and to compare the read authentication key with the obtained authentication key in order to perform a mutual authentication; an update module configured to read the media unique key and one of the first and second application keys which is valid from the storage medium when the mutual authentication is successful, to decrypt the read application key by the media unique key of the storage medium, to re-encrypt a result of decryption by a media unique key of a host, to supply a result of re-encryption to the storage medium, and to update the other of the first and second application keys which is invalid; and a supply module configured to supply a media key block stored in the apparatus to the storage medium, and the storage medium comprises an update module configured to compare the media key block supplied from the information processing apparatus with the media key block stored in the storage medium in order to determine which is newer and to rewrite an old media key block stored in the storage medium with a new media key block supplied from the information processing apparatus.