Host device and authentication method for host device

Abstract

A first data generation unit generates identification key information (FKey) that may be decrypted from the identification key information (IDKey) using key management information (FKB) read from an authenticatee. A decryption unit decrypts encrypted secret identification information (E-SecretID) using the identification key information (FKey) to generate secret identification information (SecretID). A second data generation unit generates a first session key (Skey) using the first key information (Hkey) and a random number. A one-way conversion unit performs a one-way conversion process on the secret identification information (SecretID) using the generated first session key (SKey) to generate first one-way conversion data (Oneway-ID).

1 . (canceled) 
     
     
         2 . A host device 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 device key data and host device key certificate; and   an authentication unit that performs a key exchange process with an external device via the interface to output medium device key certificate ID;   an ID combining unit that combines a public controller unique ID and the medium device key certificate ID to output a unique ID;   a random number generator that generates a random number;   a one-way converter that generates medium unique key using one-way function to which the unique ID and a medium key is input;   a first encryption unit that encrypts a title key using the medium unique key; and   a second encryption unit that encrypts content data using the title key.   
     
     
         3 . The host apparatus according to  claim 2 , wherein the host device key data is a private key of a public key cryptosystem, and the host device certificate is a public key that forms a pair with the host device key data. 
     
     
         4 . The host apparatus according to  claim 2 , wherein the ID combining unit uses one-way function to generate the unique ID. 
     
     
         5 . The host apparatus according to  claim 2 , wherein the authentication unit performs the key exchange process based on elliptic curve cryptography. 
     
     
         6 . The host apparatus according to  claim 5 , wherein the authentication unit transmits the host device key certificate with an first random number to the external device. 
     
     
         7 . The host apparatus according to  claim 6 , wherein the authentication unit verifies signature received from the external device and generates a second random number for the key exchange process based on elliptic curve cryptography.