Patent ID: 7861293

Claim:
A mobile terminal including a terminal program and an IC device having a property against tamper, wherein the terminal program and the IC device perform transmission and reception of messages with respect to one another, the terminal program comprising: an identifier generation means for generating an identifier of the terminal program using both domain information and port information of the IC device prior to transmitting a request for a message to the IC device, the port information including a port number uniquely generated by the IC device and provided to the terminal program such that the terminal program has obtained a port number from the IC device that is different than a port number that any other terminal programs in the mobile terminal have obtained from the IC device; a message generation means for generating a message, a source of which is identified by the terminal program identifier generated by the identifier generation means and a destination of which is identified by an identifier of the IC device; and a transmission means for transmitting the generated message to the IC device when the identifier of the IC device is held in a hold means, and the IC device comprising: an authentication means for judging, from the terminal program identifier of the message transmitted by the transmission means, whether or not the domain information and the port information in the terminal program identifier and the domain information the port information registered in the IC device agree; and a process execution means for executing a process in accordance with the message when the authentication means judges that the domain information and the port information in the terminal program identifier and the domain information and the port information registered in the IC device agree.