On Secure, Privacy-aware, and Efficient Beacon Broadcasting among One-hop Neighbors in Vehicular Adhoc Networks

Many Vehicular Ad Hoc NETwork (VANET) applications achieve a decent packet delivery ratio using mobility information in the beacon messages broadcasted to the singlehop neighbors. Recently it has been found that if two VANET nodes are not within a line of sight (LoS), the performance of the employed VANET applications can be significantly degraded. Most of the existing VANET researches assume the ideal effective transmission range which does not consider Non-LoS (NLoS) scenario. To fill this gap, this paper provides a new mechanism: (a) to keep the track of the LoS status of individual vehicles on the road (b) to make sure that even in case of NLoS, vehicles maintain their communication with neighbors, and (c) to preserve the location confidentiality and privacy of the users conditionally at all times during communication. We propose a beacons-assisted plausibility-based technique to figure out NLoS status and a cooperative mechanism to guarantee a smooth communication between vehicles in case of NLoS. In case of NLoS, the affected vehicles raise alarms through their beacons and the neighbors with clear LoS to the target vehicles provide the affected vehicle with desired information. Moreover we maintain privacy-aware neighbor lists and location-based encryption for the aforementioned purpose and take the security of privacy of the whole system into account. Keywords—VANET, Nonline-of-sight, Cooperative comm., Effective transmission range, beacons.