Patent ID: 8015393

Claim:
A data processing device comprising: a storage unit configured to store an initial value of a pair of a public key and a private key; a communication unit configured to (i) transmit the public key stored in said storage unit to an external device, (ii) receive a session key encrypted using the transmitted public key, (iii) decrypt the received session key using the private key stored in said storage unit, and (iv) receive a new pair of a public key and a private key from the external device using the decrypted session key; an installation unit configured to install the new pair of the public key and the private key received by said communication unit; a determination unit configured to determine whether login by an administrator authority is acknowledged; an installation permission unit configured to permit said installation unit to install the new pair of the public key and the private key when the login by an administrator authority is acknowledged; and a display control unit configured to cause a display unit to display a value of the public key installed from the external device.