The Design And Application Of Data Security Storage Scheme Based On Consortium Blockchain

With the rapid development of Internet technology and the increasing degree of social informationization,all kinds of application software and electronic equipment will produce a large amount of data and data plays an increasingly important role in our life.As a result,the requirement of data storage for application software become very pervasive.For the user private data storage in the application software,the separation of data owner and data manager is easy to cause the problem of user data tampering and data leakage.At present,there are two deficiencies in the protection measures of data security that need to be perfected urgently.On the one hand,data integrity verification usually depends on trusted third-party auditors.Data managers may maliciously impersonate third-party auditors,resulting in data tampering while the user does not know,posing a threat to data integrity.On the other hand,the data storage lacks credible access records traceability.Managers can trace access records through the system run log,but the cost of tampering with the logs is low.The traceability results are incredible,so user is not aware of the occurrence of data breach events,which poses a threat to user privacy.For the past few years,in the financial,anti-counterfeiting traceability and other fields blockchain technology gradually emerged on account of the characteristics of de-trust and data can not be tampered with.According to the idea of combining blockchain with distributed storage technology,this thesis carry out the following aspects of research and design work:(1)Ethereum is an open source project of blockchain.This thesis does research into the issues from Ethereum in consortium blockchain scene.On the one hand,the Proof of Work mechanism used in Ethereum will carry out "mining" operation which consumes a lot of hashrate is not suitable as the consortium blockchain consensus mechanism.In this thesis,the Tendermint consensus algorithm is used as the Ethereum consensus mechanism,and it is improved.This thesis introduces the node credit scoring mechanism into the tendermint algorithm.The nodes with low credit rating only act as validators which avoids the poor state of the nodes responsible for producing block and improves the efficiency of the system.Besides the nodes no longer carry out "mining"operation which avoids the waste of hashrate.Ethereum,on the other hand,does not have node management operations.Therefore,the node access mechanism is designed to identify the nodes attempting to access them.System can add or delete nodes dynamically by smart contract,which can avoid malicious nodes connected to the consortium blockchain.Experimental results show that the design and implementation of the Etherueum consortium blockchain can reach a consensus under the condition that the number of failure nodes in the system is less than 1/3 nodes.And the CPU occupancy rate in the same test environment is lower than that of the Ethereum node using the Proof of Wrok mechanism.(2)According to the problem of data tampering and leakage in the current data storage process,the data storage solution based on consortium blockchain is designed.Firstly,the scheme adopts the metadata protection module based on the Ethereum blockchain.This module uses the decentration and de-trust characteristics of blockchain to complete the protection of metadata information such as data digest.It provides non-tampering metadata storage and traceability of data access records.Secondly,the scheme adopts the data storage module with Ceph cluster as the storage carrier.Ceph,as a widely used distributed storage technology,can provide reliable and easy to expand data storage ability.In addition,the data is encrypted by AES symmetric encryption algorithm and the encryption key is kept by the data owner himself which further prevents data leakage and ensures data privacy.Finally,the smart contract development language solidity support Mapping data structure imperfectly.Therefore,according to the demands of developer,the Mapping structure is further encapsulated as a library contract which provides key value management functions.The overall test of the scheme shows that the scheme uses blockchain to realize system decentralized.Users can participate in the data management process which reduces the power of data managers.Besides the scheme provides the function of data secure storage and access to record traceability.(3)This thesis analyzes people's demands in health file management and designs an electronic health file management system based on the data storage solution of consortium blockchain.According to the test,the system provides patients with the upload,access function of the health file and the traceability function of the file access record,which ensures the security and privacy of the patient's health file.To sum up,combining blockchain and ceph distributed storage,this thesis designs a data security storage solution based on consortium blockchain.The solution proposed in this thesis provides users with private data security storage and access record traceability and has potential application value.