A vehicle includes a controller. The controller is configured to perform authentication of a portable device by communication with the portable device when startup of a system of the vehicle is instructed, when the system is off, or when the startup of the system of the vehicle is instructed and the system is off. The controller is configured to perform the startup of the system of the vehicle when the startup of the system of the vehicle is instructed, under a condition that the authentication of the portable device is successful. The controller is configured to perform reauthentication of the portable device when predetermined movement of the vehicle is detected after the startup of the system of the vehicle, and perform theft prevention processing when the reauthentication of the portable device fails.