Efficient generation and distribution of CRLs for IEEE 802.11s-based Smart Grid AMI networks

In this paper, we propose a novel algorithm for reducing the size of certificate revocation lists (CRLs) created and distributed for IEEE 802.11s-based Smart Grid Advanced Metering Infrastructure (AMI) networks. Rather than maintaining a huge-size single CRL that introduces unnecessary search time and storage, the idea is to generate groups of smart meters (SMs) within the AMI network and create CRLs based on these groups. Creating groups is appropriate in AMI networks since the SMs are stationary in contrary to traditional mobile wireless networks. Our proposed grouping algorithm is based on the created paths from leaf SMs to the gateway as well as the immediate neighborhood of each SM. Via grouping, the length of the CRL for each SM and the corresponding distribution overhead can be reduced significantly. Simulation results have shown that our approach can maintain a balance between the size of the CRL and the number of signatures generated by certification authorities (CAs) while guaranteeing security of the communications.