Privacy information retrieval method and system suitable for large-scale database

Abstract

The invention discloses a privacy information retrieval method and system suitable for a large-scale database, and the privacy security of a user query target and a server database is protected by using casual polynomial transmission and Paillier homomorphic encryption. And the influence of the personalized privacy demand of the user and the bucket number on the communication overhead and the calculation cost in an actual scene is fully considered. The bucking operation and the oblivious polynomial calculation are executed on the subsets corresponding to the k keywords specified by the user, so that the overall calculation complexity can be effectively reduced, and the personalized privacy demand preference of the user in an actual scene can be met. Through the disclosed hash function, the number of times of ciphertext communication between the user and the server and the decryption operation complexity of the user can be reduced, and the response speed of private information retrieval is improved.

Description

technical field [0001] The invention belongs to the field of data security, and relates to a private information retrieval method and system suitable for large-scale databases. Background technique [0002] Private information retrieval is a privacy security technology in database query. Its application scenario is that the server provides query services to third parties. It is necessary to achieve two-way privacy between the server and the user, that is, to ensure that the query privacy preferences of the query user are not known by the server, and at the same time. It is ensured that users cannot obtain database-related information other than the target of this query. Inadvertent transmission is a key method to realize private information retrieval, but since the realization of inadvertent transmission requires encryption and decryption of the entire database data and multiple transmissions between the server and the user, the computational complexity of traditional privat...

AI Technical Summary

Problems solved by technology

Oblivious transmission is the key method to realize private information retrieval, but since the implementation of oblivious transmission requires encryption and decryption of the data in the entire database and multiple transmissions between the server and the user, the computational complexity of traditional private information retrieval methods and the size of the database into a linear relationship, making it difficult to support private information retrieval on large-scale databases

To solve this problem, existing studies have proposed methods such as database parallel retrieval, MDS code storage, and multi-round inadvertent transmission to reduce the complexity of computation or communication. and computational overhead

Considering that in many practical scenarios, users only need to implement k-anonymous privacy protection, that is, the server cannot distinguish the user's query object from k pieces of information

Images