Utilizing Advanced Metering Infrastructure to Build a Public Key Infrastructure for Electric Vehicles

component of our lives in the future which will necessitate their integration with the Smart Grid. In addition to public charging stations that are built for EV charging purposes, we are witnessing the development of home microgrids which will serve as a charging station not only for the homeowners but also for the neighborhood. Such home microgrids can be accessible through their smart meters, which makes advanced metering infrastructure (AMI) a viable alternative for vehicle-to-grid (V2G) communications. The security of these communications can be addressed by relying on a public-key infrastructure (PKI) that enables the use of certificates by the participants. However, the management of a PKI is challenging, in particular with respect to certificate revocation lists (CRLs) that need to be maintained at all times not just for the AMI network but also for the large number of EVs that will use it. Real-time access to CRLs is necessary for secure and efficient EV communications which is often needed for charge scheduling purposes. In this paper, we propose exploiting the AMI as an overlay infrastructure that keeps the CRL of EVs in a distributed hash table (DHT) and provide required security services. The proposed approach is evaluated under ns-3 by using IEEE 802.11s and IEEE 802.11p protocols. The results shows that the proposed approach enables the use of smart meters as an overlay infrastructure by significantly reducing the storage requirements for implementing PKI and providing comparable delay performance to that of a local CRL approach.