When privacy meets economics: Enabling differentially-private battery-supported meter reporting in smart grid

Millions of the smart meters, as essential components, are being deployed ubiquitously in the next generation power system. However, the public privacy concerns over the users' power consumption leakage raise, since the smart meters' unintermittent readings contain customers' behavior patterns. To alleviate this problem, the state-of-the-art techniques are common to use a rechargeable battery to hide the actual power consumption. Unfortunately, none of the existing works completely provide a rigorous privacy protection with reasonable cost under real-world battery settings, i.e., achieving the well-known differential privacy guarantee economically using batteries with limited charge/discharge rate and capacity. To attain this goal, this paper proposes a differentially private meter reading report mechanism. The main idea is to first narrow down the domain of the noise distribution parameter, in order to decrease the possibility of violating the battery limits. It also combines a multi-armed bandit algorithm to further reduce the cost as much as possible. In addition, a novel switch mechanism is proposed to prevent the meter from reporting its reading when the battery limitations might be violated. The theoretical analysis provides a formal proof of the privacy guarantee of the proposed scheme. Besides, experimental results show that the privacy protection of the proposed scheme is at least nine times stronger than that of the existing solutions with acceptable extra cost.