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.

1 . (canceled) 
     
     
         2 . A host apparatus configured to perform an authentication process, the host apparatus comprising:
 an interface configured to send data to an external device;   a storage configured to store host private key data and index data, and a media key block; and   an authentication unit that obtains medium key data by decrypting the media key block using the host private key data, generates a medium unique key in accordance with an medium ID received from the external device, and executes authentication based on the medium key data.   
     
     
         3 . The host device according to  claim 2 , further comprising a first encryption unit that encrypts title key data with the medium unique key. 
     
     
         4 . The host device according to  claim 3 , further comprising a second encryption unit that encrypts content data using the title key. 
     
     
         5 . The host apparatus according to  claim 2 ,
 wherein the external device includes a controller embedded with controller key data and value data;   the controller is configured to decrypt first encrypted private key data using the controller key data, the first encrypted private key data being generated by encrypting private key data;   the controller is configured to generate the private key data by decrypting the first encrypted private key data using   the controller key data; the controller is configured to generate second encrypted private key data by encrypting the private key data using the value data and the controller key data, and write the second encrypted private key data in the external device;   the private key data is encrypted by an organization using the controller key data;   the controller key data is embedded in the controller by a vendor that manufactures the controller, the vendor being different from the organization; and   the value data and the first encrypted private key data are inputted to the controller.