Patent ID: 8156339
Filing Date: 2012-04-10
Classification: G11B,H04L

Abstract:
1. A content usage right information providing device for providing content usage right information containing a content key for decrypting encrypted content data to a content usage right information receiving device, the content usage right information providing device comprising: a processor; a memory having a program, when executed, causing the processor to perform the following functions: an interface function for receiving from the content usage right information receiving device a first certificate containing a first public key; a verification function for verifying the first certificate; a certificate output function for outputting a second certificate containing a second public key of the content usage right information providing device; and a first encryption function for encrypting a first symmetric key by using the first public key contained in the first certificate, and concatenating the encrypted first symmetric key and the second certificate output from the certificate output function, wherein the interface function transmits the encrypted first symmetric key and the second certificate to the content usage right information receiving device and receives from the content usage right information receiving device a first encrypted second symmetric key which is encrypted by using the second public key contained in the second certificate and further encrypted by using the first symmetric key, the processor further performs the following functions: the interface function transmits the content usage right information containing the content key after the second decryption function acquires the second symmetric key.