Device Proximity Detection

摘要

A method for detecting proximity of two communicating devices is disclosed. Proximity may be determined by measuring deviation from standardized signal timing specifications. An embodiment uses inter-frame space parameters specified by the Bluetooth Low Energy protocol to do proximity detection, and presents a solution that may prevent or mitigate relay attacks. The method offers the advantage that the use of an existent frame timing protocol eliminates the need for specific hardware or firmware modifications.

主权项

1. A method comprising:
synchronizing a timing of a first device with the timing of a second device; sending a portion of data from the first device to the second device in at least one frame; sending an instruction to the second device, requesting a copy of the portion of data to be sent in a consecutive frame from the second device to the first device; storing a first time record of a trailing edge of a trailing frame of the instruction; receiving the portion of data from the second device; determining a second time record of receipt of the leading edge of a leading frame of the portion of data received by the first device; determining a time difference between the first time record and the second time record; and determining a latency value based upon the difference between a first parameter value and the time difference, wherein the latency value not greater than a deviation parameter value indicates a proximity between the first device and the second device.