Research And Implementation Of Data Privacy Protection And Traceability Based On Blockchain

In this era of big data,the privacy protection of personal information has been paid more and more attention by everyone.However,in daily life,we often need to provide our own information to network service providers to obtain better services,the possible leakage of personal information may have a negative impact on our lives,for network service providers,collecting user data can not only serve users better,but also gain potential useful value through data analysis.Therefore,network service providers may grant data to third-party organizations for data analysis,there may be behaviors of thirdparty organizations that leak data.Therefore,it is necessary to protect the personal privacy information of users,and to trace the source of data leakage in time when data leakage occurs.For privacy protection,this thesis takes the education privacy protection as an example to propose a privacy protection scheme,which is based on the blockchain platform and implemented by combining homomorphic encryption and attribute encryption technology,in addition,this thesis also proposes an attribute encryption method that can perform fine-grained access control on data content,it can obtain part or all of the data according to the attributes held by the user,and use homomorphic encryption to protect the privacy of the data,the ciphertext of homomorphic encryption can be used to obtain information without knowing the plaintext.In the key management of attribute encryption and homomorphic encryption,this thesis uses smart contracts to manage the user’s key.Facing the data traceability problem of privacy leakage,this thesis proposes a scheme that combines blockchain and digital watermarking technology to realize the traceability of leaked data sets,this thesis proposes to embed the reversible digital watermark into the data set,and then store the relevant information in the smart contract.When a data leakage occurs,the source organization of the leaked data is obtained by comparing the watermark information in the leaked data set with the information recorded in the smart contract,at the same time,in the process of granting data to a third-party organization,by using a specific encryption technology to encrypt the data access link and save it to a smart contract,only the organization that has been granted the data can decrypt and obtain the data,ensuring the security of the data granting process.