The Research On Smart Grid Privacy-Preserving Based On Blockchain

As a new type of power network,smart grid combines traditional power grid with information and communication technology to achieve more accurate power dispatching and management.In the smart grid,utility suppliers collect the electricity consumption data of all users in a period of time through smart meters,and develop power supply strategies by analyzing these data,so as to maintain the balance between power production and demand.However,attackers can collect these real-time user power data through illegal means,then analyze these data to infer users’ behavior habits.Therefore,in order to analyze real-time power data without revealing users’ privacy,privacy-preserving data aggregation schemes have been extensively researched in smart grid.However,there are some problems with existing schemes,such as allowing only fixed users,requiring a trusted center,and not being able to meet the needs of data fine-grained analysis.To solve these problems,this thesis proposes two data aggregation schemes based on blockchain.The main contents are as follows:1.Aiming at the problems of dynamic user and fault tolerance without a third-party trusted center,a blockchain-based multidimensional data aggregation scheme for smart grid is proposed.In the scheme,the leader election algorithm in Raft consensus protocol is used to select a mining node from all smart meters to verify and aggregate data.At the same time,a dynamic secret sharing homomorphism scheme is designed to realize flexible dynamic user management and fault tolerance without a trusted center.Moreover,due to the use of dynamic secret sharing technology,the secret sharing phase only needs to be executed once,reducing communication overhead.In addition,the scheme also supports multidimensional data aggregation,which can obtain the sum of all users’ electricity consumption data for each electrical appliance,thereby achieving fine-grained analysis of user power data.The security analysis shows that the proposed scheme is semantic security under the chosen plaintext attack(IND-CPA).The experimental results show that the proposed scheme has lower computation and communication overhead than other schemes.2.Aiming at the untrustworthy issue of aggregation nodes in smart grid,an edge blockchainassisted anonymous verifiable multidimensional data aggregation scheme is proposed.In the scheme,a three-tier aggregation architecture is designed based on blockchain and edge computing.Then,an improved verifiable secret sharing technique is used to treat confused power values as polynomial coefficients,so it can achieve multidimensional data aggregation without using techniques such as super-increment sequence.In the scheme,aggregated data can be verified by the polynomial commitment to determine whether the aggregation nodes have performed the correct data aggregation.Security analysis shows that the scheme can not only achieve anonymous identity authentication,but also resist internal attacks including collusion attacks by n-1 users and external attacks such as man in the middle attack and modification attack.The experimental results show that the proposed scheme is efficient under the condition of diversified electrical appliances.