Relay attack prevention

1. An unlockable device comprising:

a short-range wireless protocol communication system;

a controller comprising one or more processors; and

a non-transitory computer-readable storage medium that stores instructions for execution by the one or more processors, wherein the non-transitory computer-readable storage medium stores instructions for execution by the one or more processors to perform a method comprising:

receiving a wireless signal at the short-range wireless protocol communication system from a nomadic device, wherein the received wireless signal comprises time information comprising a first timestamp corresponding to a time value generated based on a short-range wireless communication signal that reaches a software application of the nomadic device, and a second timestamp corresponding to a time value generated when the software application transmits the short-range wireless communication signal to one or more components of the nomadic device;

determining a time-of-flight of the short-range wireless communication signal between the nomadic device and the unlockable device at least partially in response to the received first and second timestamps; and

causing an unlockable device module to perform an unlockable device function based on the determined time-of-flight.

2. The unlockable device according to claim 1 , wherein the non-transitory computer-readable storage medium further comprises instructions for execution by the one or more processors to perform:

determining a distance between the unlockable device and the nomadic device based upon the determined time-of-flight, and wherein causing the unlockable device module to perform the unlockable device function based on the determined time-of-flight comprises causing the unlockable device module to perform the unlockable device function based on the determined distance.

3. The unlockable device according to claim 1 , wherein the unlockable device is a vehicle.

4. The unlockable device according to claim 3 , wherein the unlockable device module is an electronic control unit (ECU).

5. The unlockable device according to claim 2 , wherein the non-transitory computer-readable storage medium further comprises instructions for execution by the one or more processors to perform:

determining whether the calculated distance exceeds a predetermined threshold, and generating a notification based on the calculated distance exceeding a predetermined threshold.

6. The unlockable device according to claim 3 , wherein the unlockable device function comprises a vehicle function including at least one of the following: a vehicle ignition actuation; a vehicle door lock actuation; or a vehicle door unlock actuation.

7. The unlockable device according to claim 3 , wherein the non-transitory computer-readable storage medium further comprises instructions for execution by the one or more processors to perform:

receiving an ignition request for an engine;

starting or preventing ignition of the engine based on comparing the determined time-of-flight with a predetermined threshold.

8. The unlockable device according to claim 3 , wherein the non-transitory computer-readable storage medium further comprises instructions for execution by the one or more processors to perform:

receiving an access entry request to the unlockable device; and

allowing entry or preventing entry into the unlockable device by unlocking doors or maintaining a locked state of the doors, respectively, based on comparing the determined time-of-flight with a predetermined threshold.

9. A method comprising:

establishing a short-range wireless communication link between (a) a short-range communication system on an unlockable device and (b) a nomadic device;

receiving a wireless signal at a short-range wireless communication system on the unlockable device from the nomadic device, wherein the received wireless signal comprises time information, the time information comprising one or more of: a first timestamp corresponding to a time value generated based on a short-range wireless communication signal that reaches a software application of the nomadic device, and a second timestamp corresponding to a time value generated when the software application transmits the short-range wireless communication signal to one or more components of the nomadic device;

determining time-of-flight of the short-range wireless communication signal between the nomadic device and the unlockable device at least partially in response to the received first and second timestamps;

performing an unlockable device function based on the determined time-of-flight.

10. The method according to claim 9 , wherein the method further comprises:

determining a distance between the unlockable device and the nomadic device based upon the determined time-of-flight, and

wherein performing the unlockable device function based on the determined time-of-flight comprises performing the unlockable device function based on the determined distance.

11. The method according to claim 10 , further comprising:

determining whether the calculated distance exceeds a predetermined threshold, and

generating a notification based on the calculated distance exceeding a predetermined threshold.

12. The method according to claim 9 , wherein the unlockable device is a vehicle.

13. The method according to claim 12 , wherein the unlockable device function comprises a vehicle function including at least one of the following: a vehicle ignition actuation; a vehicle door lock actuation; or a vehicle door unlock actuation.

14. The method according to claim 12 , further comprising:

receiving an ignition request for an engine;

starting or preventing ignition of the engine based on comparing the determined time-of-flight with a predetermined threshold.

15. The method according to claim 12 , wherein the unlockable device module is an electronic control unit (ECU).

16. The method according to claim 12 , further comprising:

receiving an access entry request to the unlockable device; and

allowing entry or preventing entry into the unlockable device by unlocking doors or maintaining a locked state of the doors, respectively, based on comparing the determined time-of-flight with a predetermined threshold.