This article has been accepted for publication in a future issue of this journal, but has not been fully edited. Content may change prior to final publication. IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY 1 Key Agreement Algorithms for Vehicular Communicatio

Creating secure communication channels in vehicular communication networks is an important topic that has not been well studied. A critical question is how to distribute secret keys between the communication partners. Vehicular networks typically include two different types of communication modes: vehicle-to-vehicle (V2V) and vehicle-to-infrastructure (V2I) modes. In this paper, we propose two key agreement algorithms for V2V and V2I, respectively. The first algorithm allows two legitimate users (vehicles) to derive a common secret key through an information-theoretic manner. The second algorithm uses the channel diversity property to generate a secret key between a central server and the individual user. Through evaluation, we show that the proposed V2V key agreement algorithm achieves strong information-theoretic security with a secret bit generation rate much faster than previous work. Numerical analysis also shows that the proposed V2I key agreement scheme can prevent attacks from an adversary with high probability, even if it has a large number of eavesdroppers following the target user.