On the Feasibility of Overshadow Enlargement Attack on IEEE 802.15.4a Distance Bounding

Distance-bounding protocols are able to measure a secure upper bound to the distance between two devices. They are designed to resist to reduction attacks, whose objective is reducing the measured distance. In this paper we focus on the opposite problem, the enlargement attack, which is aimed at enlarging the measured distance. We analyze the feasibility of enlargement attacks through overshadow strategies on 802.15.4a UWB distance-bounding protocols. We show that the overshadow strategies, generally considered feasible by the existing literature, are actually difficult to carry out. Depending on the delay introduced by the adversary, there are cases in which they have no effect or their effect is not controllable.