Dynamic Key Management in a Smart Grid

Abstract

This chapter extends the discussion of dynamic secrets from the secure communication between Alice and Bob to the cryptographic key management in a large scale networked environment. The deployment cost, the management complexity, and the scalability issues are addressed. Specifically, this chapter chooses the smart grid as the application scenario to explore the practicality of the key management scheme based on dynamic secrets. Smart grid is an emerging infrastructure and the directions have been changing constantly. In this chapter we make a primitive proposal for certain aspects of smart grid security assuming wide use of wireless communication devices. The smart grid is a vital integration of the traditional power grid and a communication network that enables real time information sharing and control across the grid. The communication capability among grid devices enables higher power utilization efficiency for the smart grid than the traditional power grids. However, it is challenging to architect a secure communication infrastructure to protect the smart grid from cyber-physical security threats. One major challenge is to design an efficient, scalable cryptographic key management scheme (KMS) for smart grid communication networks. A smart grid can contain millions of nodes in its communication network. These nodes can be remotely scattered, even in areas where the accessibility is severely limited, e.g. in a high latitude region where snow blocks the access road to some smart grid nodes in winter months. Such a network environment is unlike that found in typical computer network. A KMS designed for a traditional computer network will encounter performance hurdles or even be infeasible when directly applied to a smart grid communication network. This chapter presents a dynamic key management scheme (DKMS) as a lightweight, scalable key management solution for the smart grid communication network.