Research On Fog Computing And Blockchain Based Secure Data Aggregation Mechanism

With the development of wireless communication technology,various intelligent sensing devices have emerged at the historic moment.Intelligent devices can collect data and transmit the data to the cloud center for real-time observation and intelligent decision-making.Smart grid as the next generation grid,it received more and more attention.However,these smart meters will generate a large amount of data,which will bring a huge burden to the cloud.Meanwhile,the smart grid must ensure the privacy,efficiency,flexibility,security and stability in this process.With the everincreasing of the number of users connected to smart grid,it will become more difficult to address these issues.Aiming at the existing problems of smart grid incomputing and communication overheads,flexibility,security,stability,and privacy protection,the innovative contributions of this dissertation include the following three aspects:1)Fog-assisted lightweight privacy-preserving data multilevel aggregation mechanism: According to shortcomings of current data aggregation schemes in the computation cost,communication overhead,data integrity verification and flexibility,this dissertation develops a fogassisted lightweight privacy-preserving data multilevel aggregation mechanism for smart grid.Specifically,this mechanism utilizes the multi-level aggregation model of cloud-fog collaboration to enable intermediate-level fog nodes to collect data from the connected smart meters,and derive finegrained fog-level aggregation results to save communication overhead and improve the flexibility of smart grid.Meanwhile,the extended Paillier encryption algorithm,hash function,and Horner rule are used to reduce the computation cost.Finally,simulation results show that this mechanism has lower calculation and communication costs than other existing schemes.2)Double-blockchain assisted secure and anonymous data aggregation for fog-enabled smart grid: In order to further enhance the security capability to resist cyber attacks of smart grid,this dissertation proposes a double-blockchain assisted secure and anonymous data aggregation mechanism for fogenabled smart grid.Specifically,it designs a three-tier architecture based data aggregation framework by integrating fog computing and blockchain,and then develops a secure and anonymous data aggregation mechanism with lower computation overhead by jointly combining Paillier encryption,batch aggregation signature and anonymous authentication.Finally,the superiorities of the proposed mechanism are illustrated by a series of security and computation cost analyses.3)Blockchain-assisted security authentication and privacy aggregation mechanism for V2G: In order to maintain the stability of smart grid,this dissertation integrates the V2 G into the smart grid,and proposes a blockchain-assisted security authentication and privacy data aggregation mechanism for fog-based V2 G.Firstly,it designs a data aggregation framework based on fog computing and blockchain,which provides a strong support for V2 G to achieve power injection.Secondly,it jointly leverages homomorphic encryption,batch aggregation signatures and Bloom filters to effectively guarantee the security of user's identity information and privacy data and achieve secure authentication.Meanwhile,it realizes the fine-grained homomorphic aggregation for the power data injected into the grid by all Electric Vehicles,laying a foundation for the accurate and flexible power dispatching of smart grid.Finally,the extensive simulation results show that the proposed solution has lower computation cost,and it is more suitable for V2G.