Efficient Management of Certificate Revocation Lists in Smart Grid Advanced Metering Infrastructure

Advanced Metering Infrastructure (AMI) forms a communication network for the collection of power data from smart meters in Smart Grid. As the communication within an AMI needs to be secure, key management becomes an issue due to overhead and limited resources. While using public-keys eliminate some of the overhead of key management, there is still challenges regarding certificates that store and certify the public-keys. In particular, distribution and storage of certificate revocation list (CRL) is major a challenge due to cost of distribution and storage in AMI networks which typically consist of wireless multi-hop networks. Motivated by the need of keeping the CRL distribution and storage cost effective and scalable, in this paper, we present a distributed CRL management model utilizing the idea of distributed hash trees (DHTs) from peer-to-peer (P2P) networks. The basic idea is to share the burden of storage of CRLs among all the smart meters by exploiting the meshing capability of the smart meters among each other. Thus, using DHTs not only reduces the space requirements for CRLs but also makes the CRL updates more convenient. We implemented this structure on ns-3 using IEEE 802.11s mesh standard as a model for AMI and demonstrated its superior performance with respect to traditional methods of CRL management through extensive simulations.

I. Introduction

The existing power grid is currently going through a major transformation to enhance its reliability and efficiency by enabling networks of intelligent electronic devices, distributed generators, and dispersed loads [1] [2], which is referred to as Smart Grid. The concept utilizes advanced communication networks for management and coordination at different components of the Smart Grid such as power generation, transmission and distribution [3]. Advanced Metering Infrastructure (AMI) which is part of the Smart Grid distribution systems, is one of the renewed components of Smart Grid that collects smart meter data using a two-way communication network [3]. Smart meters are typically connected via a wireless mesh network with a gateway serving as a relay between the meters and the utility company. AMI network provides a multi-hop path towards the destination and thereby spanning longer distances for coverage. The advanced structure of AMI network is generally used to facilitate reduction of peak demand by monitoring the power demands over short periods and providing various rating and the effective management system based on remote metering data.