Research On Data Access Control And Trusted Sharing Mechanism Based On Blockchain

The rapid development of the new generation of information technology,such as the Internet of things(Io T),cloud computing,mobile devices,has brought vast amounts of information data.These astonishingly growing data often have inestimable application and research value.However,those data usually contain users’ privacy and sensitive information,so there is an urgent need to build a credible,secure,open and transparent data sharing mechanism.Although the traditional data sharing technology has been widely used,it also brings insurmountable disadvantages,such as access control technology,proxy re-encryption technology,which all rely on centralized third-party entities.This creates some problems,such as an opaque data sharing process,incomplete knowledge of participants,single point of failure,etc.Blockchain technology has the characteristics of decentralization,untamperability and data traceability.So it is widely used in various fields,which can be used to build a transparent,open,secure and reliable data sharing environment.At the same time,it can be used to control,verify and audit the third-party access to data.In this paper,we use the blockchain to improve and expand the traditional technology of data sharing.So the traditional security technology can adapt to the increasing needs of data sharing.In order to improve the controllability and confidentiality in the process of data sharing,this paper comprehensively uses the technologies of blockchain,access control,proxy re-encryption and searchable encryption to construct a decentralized data access control and trusted sharing mechanism.The main research work is as follows:1.In the application scenario where the data is stored in the semi-trusted centralized storage service providers,the existing centralized access control scheme has some defects,such as the opaque authorization process.This paper proposes a fine-grained and auditable access control model based on blockchain.Taking blockchain as a decentralized access control manager,we combined the attribute-based access control(ABAC)model and the searchable encryption algorithm(SE).In our system,there are three types of smart contracts and data collaborative interaction mechanisms are designed and deployed,which can provide flexible fine-grained and auditable access control management functions for data sharing.2.In the application scenario where the data is stored in the untrusted distributed storage system,the existing encrypted data sharing schemes have some problems,such as high computing and communication overhead,low efficiency,etc.This paper combines the threshold proxy re-encryption technology with blockchain technology,which takes the blockchain as a decentralized key manager to provide secure and efficient key distribution and sharing function.A blockchain consensus mechanism based on threshold proxy re-encryption is designed,which improves the performance and reliability of the ciphertext conversion process,eliminates the dependence on the third-party central server.Moreover,this mechanism can effectively solve the problems of collusion attacks and performance bottlenecks.3.Based on the Hyperledger Fabric blockchain development platform,we have built a data access control and security sharing system.Combined with specific application scenarios,on the basis of security threat analysis,the model and architecture proposed in this paper are verified and evaluated.