Patent ID: 7158641

Claim:
A recording device ( 110 ) for receiving and recording data encrypted with a first public encryption key (KPm(i)) predetermined with respect to the recording device, and used for decrypting encrypted content data, comprising: a first key holding portion ( 1421 ) for holding a first private decryption key (Km(i)) being asymmetric to said first public encryption key and used for decrypting data encrypted with said first public encryption key; a first decryption processing portion ( 1422 ) for receiving a license key encrypted with said first public encryption key, and decrypting the received data with said first private decryption key; a second key holding portion ( 1450 , 1451 ) for holding at least one secret unique key (K(i)) being unique to said recording device and being symmetric in a symmetric key cryptosystem; a first encryption processing portion ( 1452 ) for receiving and encrypting said license key again with said secret unique key; a recording portion for receiving and storing the output of said first encryption processing portion; and a second decryption processing portion ( 1454 ) for decrypting said license key stored in said recording portion with said secret unique key.