INFORMATION UPDATE SYSTEM AND METHOD, VEHICLE, CHARGER AND SERVER APPARATUS

In the present invention, an information update system is equipped with an automobile (10), a plurality of chargers (20) and a server device (30). When a battery is charged, the automobile acquires position information relating to the automobile, attaches a first signature and sends this position information with the first signature attached to one of the chargers. The one charger attaches a second signature to the position information with the first signature attached. Further, the one charger sends to the automobile identification information relating to the one charger with a third signature attached. Further, the automobile attaches a fourth signature to the identification information with the third signature attached. The automobile or the one charger sends to the server device the position information with the first and second signatures attached and the identification information with the third and fourth signatures attached. The server device updates stored position information on the basis of the transmitted position information and identification information.