Verifiable Multi-user Dynamic Searchable Symmetric Encryption with Forward and Backward Privacy Feasible for Cloud Storage

With the evolution of cloud storage, data outsourcing has become a common trend. While cloud storage provides convenient services, its privacy and security issues have also attracted widespread attention. Dynamic searchable symmetric encryption (DSSE) provides an efficacious means of addressing data privacy issues by allowing data owners to directly perform retrieval or update operations on data while it is stored in the cloud. However, traditional DSSE cannot meet the needs of multi-user scenarios in practical applications. In addition, DSSE implements forward privacy and backward that is resistant to file-injection attack and support validation of search results. Therefore, we present verifiable multi-user dynamic searchable symmetric encryption with forward and backward privacy feasible for cloud storage (VM-DSSE-FB). The scheme constructs a DSSE framework that satisfies both forward and backward privacy by fusing symmetric encryption with homomorphic addition and bitmap indexing techniques. Meanwhile, we set up an encrypted update queue for each user to adapt to the requirements of multi-user scenarios. In addition, with the help of bitmap indexing and logic AND operations, we realize the accurate multi-keyword query function. In particular, the cloud server returns the search results with a workload proof to realize the effective verification of the integrity and correctness of the search results. Security analysis proves that VM-DSSE-FB approach achieves adaptive security. The performance analysis shows that compared with existing similar schemes, VM-DSSE-FB achieves more functionality while improving efficiency and is more suitable for cloud storage services.