Many significant functionalities of vehicular ad hoc networks (VANETs)
require that nodes have knowledge of the positions of other vehicles, and
notably of those within communication range. However, adversarial nodes could
provide false position information or disrupt the acquisition of such
information. Thus, in VANETs, the discovery of neighbor positions should be
performed in a secure manner. In spite of a multitude of security protocols in
the literature, there is no secure discovery protocol for neighbors positions.
We address this problem in our paper: we design a distributed protocol that
relies solely on information exchange among one-hop neighbors, we analyze its
security properties in presence of one or multiple (independent or colluding)
adversaries, and we evaluate its performance in a VANET environment using
realistic mobility traces. We show that our protocol can be highly effective in
detecting falsified position information, while maintaining a low rate of false
positive detections.