Content data storage

A content reproduction apparatus decrypting encrypted content data for reproduction of content data, comprising:

• a data storage unit detachable from said content reproduction apparatus, storing said encrypted content data and a content decryption key supplied individually apart from said encrypted content data, and required to decrypt said encrypted content data, and providing said content decrypting key in an encrypted state, and
• a data reproduction unit receiving an output from said data storage unit to reproduce said encrypted content data,
• wherein said data reproduction unit comprises
• first decryption means for carrying out a decryption process using a first symmetric key, based on said encrypted content decryption key from said data storage unit to extract said content decryption key,
• second decryption means receiving and decrypting said encrypted content data read out from said data storage unit using an output of said first decryption means to extract content data, and
• a plurality of authentication data hold means, each for storing a plurality of authentication data that are configured to be authenticated respectively with respective plurality of public authentication keys, and allowing output to said data storage unit,
• said plurality of authentication data having a predetermined value predefined during fabrication of said content reproduction apparatus, and being configured to authenticate a first public encryption key corresponding to a type of said content reproduction apparatus with respective said plurality of public authentication keys,
• select means for selectively providing data from said plurality of authentication data hold means outside of said data reproduction unit according to a request external to said data reproduction unit,
• first key hold means for storing a first private decryption key asymmetric to said first public encryption key, and used to decrypt data encrypted with said first public encryption key,
• third decryption means receiving a second symmetric key encrypted with said first public encryption key from said data storage unit for decrypting the received second symmetric key using said first private decryption key,
• session key generation means for generating said first symmetric key, and
• session key encryption means for encrypting said first symmetric key to be used for encryption of said content decryption key using said second symmetric key for provision to said data storage unit
• wherein said data storage unit comprises control means conducting an authentication process based on said authentication data from said select means to determine whether to output said encrypted content decryption key to said data reproduction unit based on an authentication result for controlling output to output said encrypted content decryption key that is encrypted with said first symmetric key when determination is made to output said content decryption key to said data reproduction unit.

A content reproduction apparatus to decrypt encrypted content data using a content decryption key for reproduction, loaded with a license information storage apparatus storing said encrypted content data and a content decryption key supplied individually apart from said encrypted content data, and required to decrypt and reproduce said encrypted content data, comprising:

• first decryption means for performing decryption using a first symmetric key based on said content decryption key from said the license information storage apparatus to extract said content decryption key,
• second decryption means receiving and decrypting said encrypted content data read from said the license information storage apparatus using an output of said first decryption means to extract content data, and
• a plurality of authentication data hold means each for storing a plurality of authentication data that are configured to be authenticated using respective plurality of authentication keys stored in said license information storage apparatus, and allowing output to said license information storage apparatus,
• said plurality of authentication data having a predetermined value predefined during fabrication of said content reproduction apparatus, and being configured to authenticate a first public encryption key corresponding to a type of said content reproduction apparatus with respective said plurality of public authentication keys,
• select means for selectively providing one of said plurality of authentication data to said the license information storage apparatus for output,
• first key hold means for storing a first private decryption key asymmetric to said first public encryption key, and used to decrypt data encrypted with said first public encryption key,
• third decryption means receiving a second symmetric key encrypted with said first public encryption key from said license information storage apparatus for decrypting the received second symmetric key using said first private decryption key,
• session key generation means for generating said first symmetric key, and
• session key encryption means for encrypting said first symmetric key to be used for encryption of said content decryption key using said second symmetric key for provision to said license information storage apparatus.

A license information distribution system to distribute encrypted content data, and license information supplied individually apart from said encrypted content data and that allow reproduction of at least said encrypted content data, comprising:

• a server to distribute said license information including a content decryption key used to decrypt said encrypted content data, and
• a reception terminal receiving said distributed license information,
• wherein said reception terminal comprises
• data storage unit detachable from said reception terminal for storing said encrypted content data and a content decryption key required to decrypt said encrypted content data, and providing said content decryption key in an encrypted state,
• wherein said data storage unit comprises
• first storage means for storing said encrypted content data,
• second storage means for storing at least a portion of said license information distributed by said distribution system, and
• a plurality of first authentication data hold means each for storing a plurality of authentication data that are configured to be authenticated by respective plurality of said public authentication keys common to said distribution system,
• said plurality of authentication data having a predetermined value predefined during fabrication of said data storage unit, and that being configured to authenticate a first public encryption key corresponding to a type of said data storage unit with respective said plurality of public authentication keys,
• first select means for selectively providing authentication data from said plurality of first authentication data hold means outside of said data storage unit according to a request external to said data storage unit,
• first key hold means for storing a first private decryption key asymmetric to said first public encryption key, and used to decrypt data encrypted with said first public encryption key,
• first decryption means receiving a first symmetric key encrypted with said first public encryption key from said server for decrypting the received key with said first private decryption key,
• session key generation means for generating a second symmetric key,
• session key encryption means for encrypting said second symmetric key used for encryption of said license information said first symmetric key to supply the encrypted key to said server, and
• session key decryption means receiving said license information supplied from a supply source of said license information, and encrypted with said second symmetric key for decryption with said second symmetric key,
• wherein said server comprises first control means to conduct an authentication process based on said authentication data from said data storage unit for encrypting said license information using said second symmetric key for distributing said license information when authentication is valid.

A content reproduction apparatus decrypting encrypted content data using a content decryption key supplied individually apart from said encrypted content data and required to decrypt said encrypted content data for reproduction of content data, comprising:

• first decryption means for applying a decryption process using a first symmetric key based on said content decryption key that is encrypted and supplied to extract said content decryption key,
• second decryption means receiving and decrypting said encrypted content data using an output of said first decryption means to extract content data, and
• a plurality of authentication data hold means each for storing a plurality of authentication data that are configured to be authenticated using respective plurality of public authentication keys, and allowing output outside said content reproduction apparatus,
• said plurality of authentication data having a predetermined value predefined during fabrication of said content reproduction apparatus, and being configured to authenticate a first public encryption key corresponding to a type of said content reproduction apparatus with respective said plurality of public authentication keys,
• select means for selectively providing data from said plurality of authentication data hold means to outside of said content reproduction apparatus for output according to a request external to said content reproduction apparatus,
• first key hold means for storing a first private decryption key asymmetric to said first public encryption key, and used to decrypt data encrypted with said first public encryption key,
• third decryption means receiving a second symmetric key encrypted with said first public encryption key for decrypting with said first private decryption key,
• session key generation means for generating said first symmetric key, and
• session key encryption means for encrypting said first symmetric key to be used for encryption of said content decryption key using said second symmetric key for provision to outside of said content reproduction apparatus.

A content reproduction apparatus receiving encrypted content data and a content decryption key supplied individually apart from said encrypted content data, and required to decrypt said encrypted content data to decrypt said encrypted content data using said content decryption key for reproduction, comprising:

• first decryption means for applying a decryption process using a first symmetric key based on said content decryption key that is encrypted to extract said content decryption key,
• second decryption means receiving and decrypting said encrypted content data using an output of said first decryption means to extract content data, and
• a plurality of authentication data hold means each for storing a plurality of authentication data that are configured to be authenticated using respective plurality of authentication keys,
• said plurality of authentication data having a predetermined value predefined during fabrication of said content reproduction apparatus, and being configured to authenticate a first public encryption key corresponding to a type of said content reproduction apparatus with respective said plurality of public authentication keys,
• select means for selectively providing one of said plurality of authentication data to a license information storage apparatus,
• first key hold means for storing a first private decryption key asymmetric to said first public encryption key, and used to decrypt data encrypted with said first public encryption key,
• third decryption means receiving a second symmetric key encrypted with said first public encryption key for decrypting with said first private decryption key,
• session key generation means for generating said first symmetric key, and
• session key encryption means for encrypting said first symmetric key to be used for encryption of said content decryption key using said second symmetric key for output.