UPriv-AC: A Privacy-Preserving Mechanism for Smart Metering Against Curious Utility

In smart grids, smart meters replace traditional meters, enabling near real-time communication between customers and companies. The metering data serves for billing, monitoring, and service delivery. However, the interception of a third malicious entity, or the data misuse by the utility could expose customer privacy. The solutions in the literature to protect the privacy of end-users discuss techniques such as data aggregation, homomorphic encryption, and the use of pseudonyms. However, they don't solve the problem of the curious utility. In this article, we propose the UPriv-AC, a meter data privacy protection mechanism with blind signature and data aggregation. The blind signature allows a certified registry of consumption per user, but preventing the utility from mapping the certified pseudonyms to their respective meters. The proposed aggregation, performed by the meters in a decentralized way, protects users' privacy from curious aggregators and the user's identification through the network interface. Hence, our mechanism allows a proper network monitoring, but stopping the utility from building consumer profiles that could reveal users habits and possessions. We analyzed our proposal in comparison with others in the literature. The blind signature proved to be more secure and with 50% lower CPU usage than the partially homomorphic encryption.