Study On Private Information Retrieval Method During Cooperation

At present, the study on problem of Private Information Retrieval has become a focus in the research of secure multi-party computation. Because of playing a very important role in database applications, Private Information Retrieval is widely used in commercial cooperation, medical research, intelligence cooperation, etc. A deeper research of Private Information Retrieval during cooperation based on the comprehensive analysis of studies at home and broad is presented in this papaer. More details are as follows.First of all, the basic theories of database encryption, encryption algorithms and definitions of secure multi-party computation are introduced correspondingly. The advantages and disadvantages of existing methods of Private Information Retrieval are analysed, which offers a solid theoretical basis for Private Information Retrieval during cooperation.Secondly, the technology of Private Information Retrieval during cooperation was studied. By the support of the indistinguishability and the theory of commutative encryption function, the any third party is introduced aiming at the responsibility of sharing computation and protecting private information from being leaked in the method. Its correctness and security are certified. Furthermore, the technology of intersectin and equijoin of Private Information Retrieval was studied. Based on the research of Private Information Retrieval during cooperation, the PIR-I algorithm of solving intersection and PIR-E algorithm of solving equijoin by any third party are proposed consecutively. Its correctness and security are certified, meanwhile its time complexity is analysed.Finally, the experimentation is presented to testify the correctness and security of the Private Information Retrieval during cooperation. Charts are demonstrated and the results are analysed in the paper.