Vehicle anti-theft device, vehicle anti-theft method, and computer program

A vehicle anti-theft method including steps of:

• registering IDs each included in information transmitted from a predetermined mobile device having an ID and received by a radio receiver;
• measuring the intensity of the radio wave received from the mobile device;
• and
• determining a vehicle being in a stolen state when a movement of the vehicle is detected while no information including a registered ID is received at that time;
• wherein:
• the step of registering includes:
• a first registration step for registering a first ID received by the radio receiver in a predetermined procedure as an ID of a mobile device belonging to an owner group;
• and
• a second registration step for registering a second ID received by the radio receiver together with the ID registered in the first registration step and the degree of change in the reception radio wave intensity from the mobile device having the second ID being similar to that from a mobile device having an ID registered in the first registration step as an ID of a mobile device belonging to a concerned person group;
• and
• the step of determining is executed in a state where it is received no ID registered in the first registration step or in the second registration step at that time.

A computer program executed by a processor of a vehicle anti-theft device provided in a vehicle when installed in the processor to perform steps of:

• registering IDs each included in information transmitted from a predetermined mobile device having an ID and received by a radio receiver;
• measuring the intensity of the radio wave received from the mobile device;
• and
• determining a vehicle being in a stolen state when a movement of the vehicle is detected while no information including a registered ID is received at that time;
• wherein:
• the step of registering includes:
• a first registration step for registering a first ID received by the radio receiver in a predetermined procedure as an ID of a mobile device belonging to an owner group;
• and
• a second registration step for registering a second ID received by the radio receiver together with the ID registered in the first registration step as an ID of a mobile device belonging to a concerned person group and the degree of change in the reception radio wave intensity from the mobile device having the second ID being similar to that from a mobile device having an ID registered in the first registration step;
• and
• the step of determining is executed in a state where it is received no ID registered in the first registration step or in the second registration step at that time.