METHOD AND DEVICES FOR SECURE MEASUREMENTS OF TIME-BASED DISTANCE BETWEEN TWO DEVICES

摘要

In order to provide a secure measurement of Round Trip Time (RTT), thecalculation of RTT and the authentication data are separated. A device A (212)sends a message (222) to device B (216) to start the method. Both devicesgenerate (224; 226) a random number (Random_A, Random_B) and device A waits(228) for device B to finish. Device A sends (242) its random number to B,which answers (246) with its own random number, and device A calculates (250)the RTT. If the RTT is below a certain limit, device A then requires (252)authentication data, which is calculated (262) by device B and sent (264) todevice A that verifies (266) the authentication data. The RTT can thus besecurely calculated regardless of the calculating resources of device B.Alternate embodiments, a system and devices are also provided.