SG-Audit: An Efficient and Robust Cloud Auditing Scheme for Smart Grid

Cloud auditing allows users to leverage digital signature evidences to undertake remote data verification and consequently determine the integrity of their data stored in the cloud. While there are many cloud auditing schemes proposed for cloud services, deployments on large scale smart grid (SG) are known to be challenging in practice, for example in terms of inefficiency and lack of robustness. In this article, we propose an efficient and robust cloud auditing scheme for SG (hereafter referred to as SG-Audit). Specifically, we utilize mobile edge computing (served as proxy signer) to offload the signature computation loads incurred by smart meters (SMs), as well as devising an efficient proxy signer recommendation strategy to ensure each SM obtains high quality service, a scalable index structure to reduce the signature evidence access time during data verification, and a deduplication and sampling based challenge data index generation strategy to narrow down the verification scope. Moreover, we also define three strategic threat scenarios supported by SG-Audit, and further devise a secure cloud auditing protocol to improve robustness. Through rigorous mathematical analysis and extensive experiments, we demonstrate that SG-Audit achieves increased auditing efficiency (by about 42% on average) in comparison to prior work.