Artificial Fast Fading-Aided Key Agreement Algorithm for Vehicle-to-Infrastructure Networks

The communication in vehicular ad hoc networks (VANETs) is commonly divided in two scenarios, namely vehicleto-vehicle (V2V) and vehicle-to-infrastructure (V2I). Aiming at establishing secure communication against eavesdroppers, recent works have proposed the exchange of secret keys based on the variation in received signal strength (RSS). However, the good performance of such scheme directly depends on the channel variation rate, being more suitable to the V2V scenario since, in V2I, the channel commonly undergoes slow fading. In this work we propose the use of multiple “dumb” antennas in order to artificially generate a fast fading channel so that the extraction of secret keys out of the RSS becomes feasible in a V2I scenario. Numerical analysis shows that the proposed model can outperform, in terms of secret bit extraction rate, a frequency hopping-based method proposed in the literature.