Patent ID: 8375206

Claim:
A data processing system comprising: a recording and reproducing apparatus having a processing section configured to receive a command identifier and encrypted data from an external apparatus; and a recording apparatus configured to be installed in and removed from the recording and reproducing apparatus, the recording apparatus having an encryption processing section for executing encryption processing on the encrypted data transmitted to and from said recording and reproducing apparatus, said encryption processing section including a control section operable to receive said command identifier in accordance with a pre-defined setting sequence, to retrieve a command from a register based on said command identifier, and to have said command executed on the encrypted data, said recording apparatus further including a command register for storing said command in accordance with said pre-defined setting sequence, wherein when said command identifier differs from said pre-defined setting sequence, said control section is operable to cancel execution of said command, said pre-defined setting sequence being a command number setting sequence in which numbers are sequentially incremented; and a sequence set such that an authentication command identifier corresponding to a authentication processing command sequence is executed prior to a command sequence corresponding to an encryption processing command sequence for executing said encryption processing, said encryption key processing command sequence including encryption key exchange processing for encryption data stored in a storage unit in said recording apparatus, the authentication processing command sequence executing authentication processing between said recording and reproducing apparatus and said recording apparatus; and wherein said control section is operable to manage an order of command execution based on said pre-defined setting sequence and said command identifier in said encryption key exchange processing, and said control section does not accept command processing from an external apparatus, including said recording and reproducing apparatus, during command execution relating to said encryption key exchange processing when said command processing is different from said pre-defined setting sequence.