Abstract: A vehicle theft protecting system includes a vehicle-onboard device mounted on a vehicle and a management station installed at a predetermined location, each including narrow area wireless communication unit capable of communication with encryption in a range of a predetermined distance to perform regular mutual communication to monitor each other's condition. The vehicle-onboard device and the management station effect mutual verification through the narrow area wireless communication at start of the mutual communication.

Abstract: An ad-hoc communication system, a mobile terminal, a center, an ad-hoc communication method and an ad-hoc communication program, in which information is directly communicated each other among mobile terminals mounted on vehicles to raise information accuracy while ensuring privacy. The center issues an ad-hoc ID with an expiration date for uniquely specifying the vehicles to deliver this ad-hoc ID to the vehicles. The center collects an ad-hoc identification of a mobile terminal exhibiting a different tendency from other mobile terminals and a report extracting information concerning the tendency, calculates reliability and bias of information produced by the mobile terminal included in the report on the basis of the report, and implants the reliability and bias of the information in the ad-hoc identification. The center puts a signature on the ad-hoc identification to prevent tampering of the ad-hoc identification.

Abstract: A vehicle theft protecting system includes a vehicle-onboard device mounted on a vehicle and a management station installed at a predetermined location, each including narrow area wireless communication unit capable of communication with encryption in a range of a predetermined distance to perform regular mutual communication to monitor each other's condition. The vehicle-onboard device and the management station effect mutual verification through the narrow area wireless communication at start of the mutual communication.