Apparently Apple does something similar to this in order to unlock Macbooks with an Apple Watch. I don't have a link right off the bat, but I remember watching

Apparently Apple does something similar to this in order to unlock Macbooks with an Apple Watch. I don't have a link right off the bat, but I remember watching an interview with Craig Federighi where he explains that the Apple Watch uses precise timers to ensure that users are actually near their computers to avoid relay attacks.