Blockchain-enhanced Smart Grid has attracted a lot of attention from scholars in recent years, due to its excellent decentralization, anti-collusion and immutability. With the wide deployment of blockchain and the popularity of more accurate intelligent applications, its role in Smart Grid is becoming more and more irreplaceable. However, because of the threat of quantum computer, it still confronts the risk of privacy disclosure. In this paper, we propose a novel and dynamic range query privacy-preserving scheme for blockchain-enhanced Smart Grid based on lattice. In this scheme, lattice-based homomorphic encryption algorithm is designed to resist the attack of quantum computer and realizes data aggregation to improve efficiency. In particular, this article designs a dynamic range query method with the aid of consortium blockchain by using proxy re-encryption. This method avoids the communication pressure caused by repeated data collection and improves the query efficiency and user experience. In addition, dynamic ciphertext and users update are considered, which further improves the flexibility and feasibility of the scheme. Last but not least, security analysis, exhaustive performance analysis and experiments show that our proposed scheme meets the requirements of dynamic, privacy, security and low computational cost.

With the advent of the era of Industry 4.0, blockchain-enhanced Smart Grids have received widespread attention from academics and industry personnel, with its great advantages in high transparency, flexibility, and decentralization. However, there are still problems of privacy leakage and inefficiency. In this article, we propose a cross-domain verifiable data collection and privacy-persevering sharing scheme based on lattice in blockchain-enhanced Smart Grids, called VC-DCPS. First, lattice-based homomorphic encryption and spatial–temporal aggregation technology are utilized to enable cross-domain collection of data, dynamic addition and deletion of users and improvement of efficiency. Second, a post-verification method is designed to verify whether the outsourcing cloud executes predetermined operations correctly. Using consensus and incentive mechanisms via smart contract will enable flexible access control and efficient transactions on the blockchain. In addition, formal security analysis shows that the proposed scheme can ensure privacy and enhance security. Finally, performance evaluation and experimental comparison are performed and turn out that the proposed scheme is strong security, high efficiency, and low storage overhead.