| With the continuous and in-depth advancement of the national big data strategy,big data applications typically represented by e-government,medical,and health industries have brought significant and far-reaching impacts on economic and social development,state management,social governance,and people’s lives.However,in the process of increasing data aggregation in different fields,the issue of privacy protection in cross-domain data sharing has also become a major hidden danger.At this time,it is usually necessary to introduce a trusted third party to integrate data from different sources and perform some privacy protection operations at the global level.Although the blockchain can well replace trusted third parties to achieve safe and reliable cross-domain data sharing,the alliance chain and smart contract technology in the existing blockchain still have major security risks and performance limitations,and cannot be directly applied In big data cross-domain data analysis scenarios.Therefore,it is necessary to conduct research and analysis on its security,scalability,and feasibility.At present,there are certain problems in the multi-party data-sharing scheme based on the alliance chain.For example,the proxy re-encryption mechanism is used to achieve data access control,but the storage pressure of the alliance chain on the key is not considered;the ciphertext calculation of data is realized by using homomorphic encryption,without considering the computing power consumption accompanying homomorphic encryption;And the existing alliance chain data multi-party sharing scheme cannot realize the security verification of the transaction data source.In response to the above problems,this thesis conducts research and analysis on multiparty data sharing based on the alliance chain.Specifically,the main research content of this thesis includes the following three aspects:(1)Aiming at the problem of data sharing based on consortium chains in big data scenarios,a multi-party data sharing framework based on dual consortium chains is proposed.Divide the data buyers and data sellers into two alliance chains,introduce notary nodes,use smart contracts as tools,and use IPFS clusters to store required data,effectively eliminating the risk of data sellers’ local data privacy leakage.Combined with the specific federated learning data analysis scenario,this thesis proposes a multi-party data-sharing scheme based on dual consortium chains.Through comparative analysis,it is verified that this scheme can effectively prevent man-in-the-middle attacks,replay attacks,51% attacks,Sybil attacks,etc.Through the analysis of its time consumption through experiments,it is verified that this scheme has certain feasibility and implementability in actual scenarios.(2)Aiming at the problem of transaction data source verification in consortium chains,a transaction data source verification mechanism based on zero-knowledge proof is proposed.The identity authentication based on asymmetric encryption and the zero-knowledge proof based on Pedersen commitment is applied to the consortium chain so that the aggregation node can verify the identity of the data transaction participants and the authenticity of the transaction without interacting with any other nodes.And it is impossible to know the private information of the transaction party,thereby improving the security of the alliance chain system.Through experimental analysis,it is verified that this mechanism is effective and feasible,and it is suitable for batch aggregation commitment verification.(3)According to the above-mentioned dual consortium chain multi-party data sharing framework and data verification mechanism based on zero-knowledge proof,considering the platform characteristics of the consortium chain and the characteristics of the zero-knowledge proof scheme,the multi-party data security based on the dual consortium chain is designed and implemented shared system.This thesis describes and demonstrates the system from four aspects: system design,environment configuration,function verification,and performance verification,and finally shows that the system has certain feasibility and usability in real scenarios. |
