A dynamic key distribution protocol for PKI-based VANETs

Secure communication in Vehicular Ad hoc Networks (VANETs) can be achieved through a public key infrastructure (PKI). A tamper proof device (TPD) is traditionally used to statically store encryption keys in each vehicle. These keys are renewed periodically by a certificate authority (CA). In this paper, a dynamic key distribution protocol for PKI-based VANETs is proposed. A vehicle dynamically requests a key from its nearest road side unit. This request is securely propagated through network infrastructure to reach a CA cloud and a key is returned. A proposed key revocation mechanism makes use of the enhanced key distribution protocol to reduce the number of messages needed for revocation. Performance analysis has been performed through network simulation to demonstrate that the proposed protocol can dynamically support efficient and cost-reduced key distribution for vehicles.