Patent ID: 7797537

Claim:
A mobile terminal comprising: a near-field communication device configure to perform near-field wireless communication with an external reader/writer device; and a controller configured to instruct: (a) the external reader/writer device to execute a first command; and (b) the near-field communication device to execute a second command; the near-field communication device including: (a) a storage unit including: (i) a controller authentication key storage area for storing a controller authentication key used for mutual authentication with the controller; and (ii) an external reader/writer device access key storage area for storing an external reader/writer device access key used for accessing the external reader/writer device; (b) a first mutual authentication unit configured to: (i) in response to a mutual authentication request given by the controller, authenticate the controller as being valid based on the controller authentication key; and (ii) request the controller to authenticate the near-field communication device as being valid; (c) a first communication key setting unit configured to set a first communication key used between the controller and the near-field communication device based on a result of the authentication operation performed by the first mutual authentication unit; (d) a second mutual authentication unit configured to: (i) in response to a mutual authentication request applied between the near-field communication device and the external reader/writer device given by the controller, authenticate the external reader/writer device as being valid based on the external reader/writer device access key; and (ii) request the external reader/writer device to authenticate the near-field communication device as being valid; and (e) a second communication key setting unit configured to set a second communication key used between the near-field communication device and the external reader/writer device based on a result of the authentication operation performed by the second mutual authentication unit; and wherein: (a) the controller and the near-field communication device, which have authenticated each other, perform secure communication using the first communication key; and (b) the near-field communication device and the external reader/writer device, which have authenticated each other, perform secure communication using the second communication key.