Blockchain-Based Trust Management Method For Power Internet Of Things Terminal Equipment

With the deeper application of Internet of Things(IoT)in industry and life,its security has received more and more attention.The large-scale and distributed characteristics of IoT system and the heterogeneity and complexity of IoT network structure make IoT face more security risks.Traditional security methods such as encryption and authentication are difficult to identify and resist internal attacks initiated by infected devices.Trust management technology is considered to be an effective way to solve network internal security problems.This thesis used Power Internet of Things(PIoT)as specific application scenario to studied its trust management issues.PIoT is a smart service system around each link of power system with comprehensive state perception and efficient information processing by fully applying modern information and communication technologies.However,the application of trust management in PIoT has problems such as one-sided trust evaluation,unreliable trust parameter storage and sharing,difficulty in proving trust data.Blockchain technology with the characteristics of decentralization and non-tamperability brings new opportunities to solve the above problems.This thesis fully considered the network characteristics and trust management requirements of PIoT,researched on blockchain-based trust management method for power internet of things terminal equipment.The research contents are as follows:First,this thesis built a system-level PIoT adaptive terminal trust model based on information entropy.Used beta distribution as statistical probability model of direct trust.Assigned weights to different trust values based on information entropy theory.Proposed a comprehensive trust value of multiple evaluation subjects as the network’s final trust of node.Evaluation indicators improved the accuracy and robustness of trust management.Secondly,this thesis proposed a blockchain-based PIoT terminal trust consensus architecture.Using blockchain as trust management carrier,the features such as nontampering and traceability can ensure storage security of trust parameter data writtend on the chain,smart terminal devices participating in the maintenance of blockchain can obtain other devices’ reputation information from the local ledger.Realized the reliable sharing of trust parameters in the network.Then,this thesis designed a blockchain consensus mechanism and bookkeeping right selection method suitable for trust management.Proposed five consensus mechanism criteria: existence criteria,uniqueness criteria,incremental criteria,symmetry criteria and successive criteria to verify the legitimacy and authenticity of trust parameters,realized the early identification of untrusted nodes,relate blockchain’s bookkeeping rights distribution principle with the proposed comprehensive trust value,improved the reliability of bookkeeping nodes.Finally,this thesis determined a validity verification strategy of trust data for lightweight PIoT terminal.Analyzed technical advantages of the Merkle Mountains technology in the lightweight verification of trust data,constructed a new block structure that introduced the Merkle Mountains,designed a lightweight trust data proof generation and verification method on this basis to reduce the storage space occupied by the proof information,improved the calculation efficiency of root node generation and update.