VPSearch+: Achieving Verifiability for Privacy-Preserving Multi-keyword Search Without Client Storage Overhead

Searchable Encryption (SE) makes it possible to query encrypted data stored on the cloud server while ensuring data and queries privacy. Most SE schemes assume that the cloud server is “honest-but-curious”, that is the cloud server strictly follow the specified protocol or algorithm, they don’t consider whether the results returned by the cloud server is really correct. In practical, in order to reduce the calculation cost, it is possible that the cloud server only completes part of the computing tasks of the protocol and returns wrong computing results to users. Therefore, it is very important for users to be able to verify the search results returned by the cloud server. To address above problem, we explore a Verifiable Privacy-preserving multi-keyword Search without client storage overhead scheme in this paper, called VPSearch+, which integrating symmetric-key hidden vector encryption with a privacy-preserving multi-keyword search scheme. Compared with TDSC’18 scheme, our proposed scheme can verify the search results quickly without storing a local copy of the outsourced data, radically reducing the storage overhead of the client in the verifiable SE scheme. Finally, the security analysis proves the high security of our model, and extensive experiments conducted on real-world dataset demonstrate that the proposed scheme can achieve better performance in terms of efficiency and storage overhead.