Research On Distributed Data Access Application Scheme Based On Blockchain

With the continuous promotion of network technology in various industries,enterprises and individual users generate a large amount of data.The storage of this data is a problem that needs to be solved.The traditional storage method is cloud storage,which exists some certain security risks because of trust issues.Therefore,the research on the new storage model has great social value and practical significance.In this thesis,the status of the distributed storage field and the theory of block chain technology are studied in depth,and some problems in this field are analyzed.Starting from improving the security of user storage data,firstly,in view of the shortcomings of the block chain consensus mechanism in the storage field,a multi-group DPOS consensus algorithm based on trust is proposed;secondly,a distributed data storage model based on block chain is proposed to solve the problem of autonomous sharing of user storage information.The specific work content and innovations of this thesis are as follows:1.Aiming at the consensus needs of the distributed data storage application environment,combined with the DPOS consensus algorithm,an improved scheme of multi-group DPOS consensus mechanism based on trust is proposed.Firstly,the influence of nodes holding heavier voting value is reduced by means of multi-group election to enhance the randomness and fairness of node election stage.Then,the function of negative vote is realized by using insurance mechanism to speed up the kick out of evil nodes.Next,the credit mechanism is introduced to increase the difficulty factor for malicious nodes to obtain votes.Finally,a list of standby witness nodes is added to timely fill the vacancy that appeared after the right of bookkeeping was revoked due to the malicious behavior of nodes.At the same time,we set up an experimental platform,and analyze and verify the consensus performance of the improved scheme.Experimental results show that the improved consensus algorithm can greatly improve the probability of removing malicious nodes,and greatly improve the system security.2.In order to solve the problem of trust crisis in storage systems,this thesis builds a data sharing access control model based on block chain technology and ABE technology.By using the block chain to encrypt and decentralize the storage encryption keys,the problem of centralized key management is solved.The data owner controls the generation and distribution of keys by himself,thus achieving shared access control of the data.At the same time,through the block chain smart contract,the ciphertext keyword search function in the storage system is designed and constructed,which solves the unfair search problem brought by the centralized storage service.The bottom layer of the solution uses IPFS to store data files,which solves the security risks brought by traditional data center storage and realizes multi-node storage of data.Finally,the feasibility of the scheme is proved by experiments.