Integrity Assurance Method of Multi-Keyword Query for Encrypted Outsourced Data

As the data scale exceeds the petabyte level, more and more users outsource their local databases to third-party service providers to save local storage costs and avoid cumbersome local data management. However, because thirdparty service providers are not fully trusted, they may leak outsourced data and bring security risks to the personal privacy of data users. The service provider may also return incorrect or incomplete query results to the data user. Therefore, in this paper, we propose a Lightweight and Verifiable Multi-keyword Query Scheme for the integrity verification of multi-keyword query of outsourced data. This scheme supports multi-keyword query integrity verification and does not require a third-party auditor, combining a hash-based accumulator that provides correctness verification and a cuckoo filter that provides integrity verification to form a provably secure composite verification structure, and at the same time, it uses controllable Paillier encryption to support data update operations. This scheme strikes a balance between the cost of verification structure generation, verification object generation, and proof verification cost to enable data users to perform secure multi-keyword query while efficiently verifying the integrity of query results. The security proof and the performance analysis show that the proposed scheme is secure and efficient for practical deployment.