Research On The Implementation And Application Of Distributed Identity Management Based On Blockchain

Digital identity management is the foundation of Internet online services.In the traditional model,the user's digital identity information is managed by the identity provider and provides external authentication services.The user loses the right to control identity information,causing the leakage of user identity information,which has a serious impact user privacy.Digital identity management has gone through centralized identity management,alliance identity management,and user-centric identity management.The essence of these identity management models is that the user's identity information is concentrated in a third-party identity provider.self-sovereign identity management allows users to fully own,manage and control their own digital identities,and solve the problem of privacy leakage caused by third-party management.The decentralization,traceability and non-tamperability of blockchain technology provide new solutions for digital identity management.Identity management is the basis of authentication,authorization and access control.Research on authentication,authorization and access control based on self-sovereign identity management has important theoretical and practical significance.This thesis designs and implements a blockchain-based self-sovereign identity management system,and studies the implementation of fine-grained access control based on attribute encryption on the system and its application in intelligent traffic lights.The specific research content is as follows:1.Designed and implemented a self-sovereign identity management system based on blockchain.The system is based on the Fabric platform.All nodes registered in the system follow the W3C's Decentralized Identifier(DID)standard to realize the full life cycle management of the establishment,issuance,use and revocation of user identity and attribute certificates.The management process is decentralized.Each node can use its own identity key to issue verifiable identity attribute certificates to other nodes,which are managed and controlled by the identity attribute owner to prevent user privacy from leaking.In addition,the issuer of the certificate is responsible for the anonymous revocation of the identity attribute certificate,does not rely on a center and protects user privacy.2.Combine blockchain-based self-sovereign identity management with decentralizing attribute-based encryption technology to realize a fine-grained access control mechanism based on self-sovereign identity management,and solve that there is an identity management and authentication center by default in the attribute-based encryption scheme.The security and scalability issues brought by.In this scheme,all nodes comply with a unified attribute-based encryption public parameter set.The issuer of each identity attribute certificate is also an attribute authority.When issuing identity attribute certificates to users,they also issue attribute keys.The certificate revocation realizes the timely revocation of the attribute key at the same time,and realizes the decentralization and privacy protection of the entire process from identity attribute management,authentication,authorization to access control.3.Aiming at the existing research on autonomous control the traffic lights by vehicle,relying on the performance and scalability issues brought by a single authentication center,this thesis uses a fine-grained access control mechanism based on self-sovereign identity management to design a decentralized Intelligent traffic signal control scheme.In this scheme,the Roadside Unit RSU,the vehicle and the signal lights are the nodes of the Fabric.RSU as the attribute authority issues location and direction attribute keys for the vehicles within its range.The traffic signal light change voting protocol initiated by the vehicle uses attribute-based encryption,so that only vehicles with the same location and direction attributes can access the protocol and return voting responses.When the positive voting response exceeds a certain threshold,the traffic lights will change according to the protocol.