In-vehicle device, vehicle authentication system and data communication method

An in-vehicle apparatus, comprising: a storage unit, the storage unit stores the vehicle-mounted device ID and a PIN code, said vehicle-mounted device ID for each user and for holding secret vehicle a vehicle-mounted device ID register; a first authentication unit, the second a PIN code authentication unit based on a comparison to determine whether the vehicle-mounted apparatus is allowed to connect to the mobile terminal; and a second authentication unit, the second authentication unit performs the authentication by the first authentication unit has been requested vehicle device ID of the mobile terminal is connected , and is registered in the vehicle-mounted device ID and the vehicle device transmits the mobile terminal in response to the request by the vehicle device ID comparing to authenticate the mobile terminal; and a data transmission unit from the data transfer unit is equipped with predetermined vehicle-vehicle device of the vehicle indicates that the vehicle is obtained and the status data to the second authentication unit has been authenticated mobile terminal.