Relay station attack prevention

1 . A non-transitory storage device including machine executable instructions which, when executed by a computing resource, cause the computing resource to:

cause each of multiple antennas to transmit a respective wireless signal;

receive values indicative of a signal strength of each respective wireless signal transmitted from each of the multiple antennas;

calculate a first respective distance between each of the multiple antennas and a wireless electrical device responsive to the received values, wherein each first respective distance is associated with a radius about a corresponding one of the multiple antennas, and wherein the radii overlap in an overlap region;

calculate a position of the wireless electrical device as a point within the overlap region;

calculate a second respective distance between each antenna and the point within the overlap region;

calculate an error value as a function of the first respective distance and the second respective distance, including calculating the error value as a square root of a sum of squares of differences between the first respective distance and the second respective distance; and

disable an access control mechanism coupled to the computing resource in response to the error value being greater than an error threshold.

2 . The non-transitory storage device of claim 1 , wherein the multiple antennas comprise at least four antennas.

3 . The non-transitory storage device of claim 1 , wherein disabling the access control mechanism comprises disabling activation of an access control mechanism of a vehicle motor.

4 . The non-transitory storage device of claim 1 , wherein at least two antennas of the multiple antennas are oriented orthogonal to each other.

5 . The non-transitory storage device of claim 1 , wherein the machine executable instructions, when executed by the computing resource, cause the computing resource to sequentially transmit, by the multiple antennas, the respective wireless signals.

6 . The non-transitory storage device of claim 1 , wherein the machine executable instructions, when executed by the computing resource, cause the computing resource to simultaneously transmit, by the multiple antennas, the respective wireless signals.

7 . The non-transitory storage device of claim 1 , wherein receiving the values indicative of the signal strength of each of the respective wireless signal transmitted from each of the multiple antennas comprises receiving the values from the wireless electrical device.

8 . The non-transitory storage device of claim 1 , wherein the multiple antennas are coupled to the computing resource.

9 . A method comprising:

causing, by a control circuit, each of multiple antennas to transmit a respective wireless signal to a wireless electrical device, the multiple antennas coupled to the control circuit;

receiving, from the wireless electrical device and by the control circuit, a second signal comprising values indicative of signal strength of the respective wireless signals transmitted by the multiple antennas;

calculating, by the control circuit, a first respective distance between each of the multiple antennas and the wireless electrical device responsive the received values, wherein each first respective distance is associated with a radius about a corresponding one of the multiple antennas, and wherein the radii overlap in an overlap region;

calculating, by the control circuit, a position of the wireless electrical device as a point within the overlap region;

calculating a second respective distance between each antenna and the point within the overlap region;

calculating, by the control circuit, an error value as a function of the first respective distance and the second respective distance, wherein calculating the error value comprises calculating a square root of a sum of squares of differences between the first respective distance and the second respective distance; and

enabling, by the control circuit, an access control mechanism coupled to the control circuit responsive to the calculated error value being lower than an error threshold.

10 . The method of claim 9 , further comprising disabling, by the control circuit, the access control mechanism responsive to (a) the position of the wireless electrical device being within a threshold distance and (b) the error value being greater than the error threshold.

11 . The method of claim 9 , wherein enabling the access control mechanism is further responsive to the calculated position of the wireless electrical device being within a threshold distance.

12 . The method of claim 9 , wherein at least two antennas of the multiple antennas are oriented orthogonal to each other.

13 . The method of claim 9 , wherein causing each of the multiple antennas to transmit the respective wireless signal comprises causing each of the multiple antennas to sequentially transmit the respective wireless signal.

14 . The method of claim 9 , wherein causing each of the multiple antennas to transmit the respective wireless signal comprises causing each of the multiple antennas to transmit the respective wireless signal simultaneously.

15 . A system comprising:

a plurality of antennas;

an access control mechanism; and

a computing resource coupled to the plurality of antennas and to the access control mechanism, the computing resource configured to:

cause each of multiple antennas to transmit a first wireless signal to a wireless electrical device;

receive a second wireless signal from the wireless electrical device, the second wireless signal comprising values indicative of signal strength of the first wireless signal from each of the plurality of antennas;

calculate a first respective distance between each of the multiple antennas and the wireless electrical device responsive to the received values, wherein each first respective distance is associated with a radius about a corresponding one of the plurality of antennas, and wherein the radii overlap in an overlap region;

calculate a position of the wireless electrical device within the overlap region;

calculate a second respective distance between each antenna and the point within the overlap region;

calculate an error value as a function of the first respective distance and the second respective distance, including calculating the error value as a square root of a sum of squares of differences between the first respective distance and the second respective distance; and

disable the access control mechanism in response to the error value being greater than an error threshold.

16 . The system of claim 15 , wherein the system is a vehicle, the vehicle includes a door, and wherein the access control mechanism is configured to lock and unlock the door.

17 . The system of claim 15 , wherein the plurality of antennas comprises at least four antennas.

18 . The system of claim 15 , wherein at least two antennas of the plurality of antennas are oriented orthogonal to each other.

19 . The system of claim 15 , wherein causing each of the plurality of antennas to transmit the respective wireless signal comprises causing each of the plurality of antennas to sequentially transmit the respective wireless signal.

20 . The system of claim 15 , wherein causing each of the plurality of antennas to transmit the respective wireless signal comprises causing each of the plurality of antennas to simultaneously transmit the respective wireless signal.