Fine-grained encrypted data aggregation mechanism with fault tolerance in edge-assisted smart grids

Encrypted data aggregation can effectively achieve the preservation of users’ privacy by aggregating electricity consumption data from multiple-source smart meters, and simultaneously reduce the transmission communication overhead in smart grids. Although encryption operations ensure data confidentiality, as smart meters are resource-constrained devices, compromised private key leakage could likewise threaten users’ privacy. In this paper, we devise the fine-grained encrypted data aggregation mechanism with fault tolerance by modifying the Lifted EC-ElGamal encryption and symmetric homomorphic encryption, which could guarantee data confidentiality, even if corresponding private key is leaked. In the mechanism, edge server is integrated in smart grids to receive encrypted multidimensional electricity consumption data sent by smart meters, execute integrity checking, generate and forward corresponding verified aggregated data reports to the control center. To ensure the robustness of smart grids due to network interruption or data packet loss from smart meters to the edge server, we exploit the Shamir secret sharing technique to achieve transmission fault tolerance. Besides, dynamic subset adjustment could be utilized in the mechanism, enabling the control center to dynamically adjust users’ multidimensional electricity consumption data collection strategy according to the actual situation. We conduct security analysis and performance evaluation demonstrating the feasibility of the mechanism in the secure deployment of edge-assisted smart grids.