A Note on a Privacy-Preserving Distance-Bounding Protocol

Distance bounding protocols enable a device to establish an upper bound on the physical distance to a communication partner so as to prevent location spoofing, as exploited by relay attacks. Recently, Rasmussen and Capkun (ACM-CCS'08) observed that these protocols leak information on the location of the parties to external observers, which is undesirable in a number of applications - for example if the leaked information leads to the identification of the parties among a group of devices. To remedy this problem, these authors proposed a "Privacy-preserving" distance bounding protocol, i.e., that leaks no information on the location of the parties.