Secure Group Key Transmission Scheme for Vehicles Parked Beyond the Communication Range of Roadside Units

Abstract

With progressive developments in vehicular technology, it is expected that vehicles in the future will be able to participate in group communication even when they are parked and the ignition has been turned off. However, when the vehicle is parked beyond the communication range of the Roadside Unit (RSU), the vehicle cannot update the group key and will be unable to participate in the group communication. In this paper, we propose a group key transmission scheme for the vehicles parked beyond the RSU's communication range. For this scheme, we provide a vehicle-to-vehicle group key delivery protocol, which includes procedures for vehicle verification and group key verification. The two procedures do not include any interaction with a third party because the vehicles cannot communicate with the RSUs. Moreover, in the vehicle verification procedure, the encrypted subscription information is transmitted and verified without being decrypted, and thus privacy of the vehicle is guaranteed. We demonstrate that the proposed scheme is secure against potential attack scenarios using mathematical analysis, and show that the privacy of the participant vehicles is secured.