Patent attributes
A vehicle antitheft system includes a house security device and a vehicle security device. The house security device includes a detection unit and a transmission unit configured to transmit a notification when a state change of a predetermined security unit is detected by the detection unit. The vehicle security device includes a reception unit configured to receive the notification transmitted from the transmission unit and a function control unit configured to control a vehicle antitheft function depending on whether the notification is received by the reception unit. The function control unit is configured to release the vehicle antitheft function when the notification is not received and a regular vehicle key is used to operate a vehicle, and to restrict releasing of the vehicle antitheft function when the notification is received and the regular vehicle key is used to operate the vehicle.