Efficient and secure delivery of area-persistent safety messages in vehicular ad hoc networks

Abstract

In this thesis, we propose an adaptive mechanism for the delivery of safety messages in vehicular networks in an authenticated and privacy-preserving manner. The traditional approach to message delivery for driving safety applications running on vehicular ad hoc networks (VANETs) has been to increase redundancy, often at the sake of other applications running on the network. We argue that this approach does not accommodate the traffic conditions of crowded cities like İstanbul, and present a probabilistic method for the dissemination of area-persistent safety messages in infrastructureless vehicular networks that dynamically adapts itself to changing road conditions. Our proposed protocol utilizes short group signatures for privacy-preserving authentication, and keyed-Hash Message Authentication Codes (HMACs) with one-way hash chains to decrease computational load on Onboard Units (OBUs). We also introduce a vehicular mobility model that creates scenarios of high-speed traffic on crowded highways based on realistic assumptions, and measure the performance of the proposed protocol using scenarios generated by this model. Our simulations show that the proposed method decreases network traffic by up to 82% and shortens delivery delays by up to 13% when compared to non-probabilistic methods in highway scenarios with medium to high vehicle density.