Multi-party And Privacy-preserving Verifiable Record Linkage Based On Blockchain

With the increasing amount of data in real life,it is crucial to link data in the integrated database for decision making in the fields of finance,medical care,and government.Multi-party and privacy-preserving record linkage is the process of identifying similar records from multiple data sources,which refers to the same real-world entity without revealing any sensitive information.Most of proposed privacy-preserving record linkage schemes relied on a hypothetical trusted third party to calculate similarity score and perform data matching,but in the real applications,the security of the third party is difficult to guarantee and the accuracy of the linkage results is not satisfied.The scalability and security of privacy-preserving record linkage scheme is a huge threat.Therefore,it is especially important to design a more secure and reliable privacy-preserving record linkage scheme.This thesis propose a multi-party and verifiable privacy-preserving record linkage scheme based on blockcahin,which can efficiently identify all records from multiple data sources without revealing any data sources private information.This thesis first proposes a multi-party and homomorphic-encrypted verifiable privacy-preserving record linage based on blockchain,which combines homomorphic encryption technology with Bloom filter encoding technology to resist frequency attacks.And this scheme proposes a new storage mechanism to solve scalability problems.Based on blockchain technology,this scheme can effectively solve the semi-trusted verification problem of third parties.Then,this thesis put forward the advanced scheme,which combines with differential privacy and functional decryption technology.The proposed blockchain-based multi-party and verifiable designated linker privacy-preserving record linkage scheme can resist differential attacks and achieve a hierarchical record linkage.Security analysis shows that the proposed scheme can protect privacy of data sources frombeing threatened by strong attackers.Compared to others schemes,the proposed scheme exhibits more scalability and higher linkage quality,and can be applied to real-world application environments.