Key Management for Secure Demand Data Communication in Constrained Micro-Grids

Micro-grids allow rural and remote communities that are either not connected to the national power grid, or suffer from load shedding, to operate power networks autonomously. Like conventional power networks, micro-grids require management and billing mechanisms. Tamper-resistant meters are not economically viable so we use a resource-constrained network formed of devices with limited memory, processing and bandwidth capabilities to handle power consumption monitoring and reporting. Relying on devices with limited capacity raises the issue of trust and so, authentication is a necessity. In this paper, we propose an authentication architecture to facilitate lightweight key management over a resource-constrained platform. We structure our key management scheme to operate as a hierarchical network where the core network is connected to a more volatile edge network. A pair-wide key pre-distribution scheme with unique identifiers per device is used to initiate the authentication process. An analysis of our scheme demonstrates that it is efficient and robust against impersonation, mis-reporting, and relay attacks that are typically used to provoke power theft.