Secure multi-client data access with boolean queries in distributed key-value stores

In the era of big data processing, it is desirable to manage large volumes of data with high scalability, confidentiality protection, and flexible types of search queries. In this paper, we propose a design to store encrypted data on a cluster of distributed servers while supporting secure and authorized Boolean queries. In particular, the data owner encrypts the database with encrypted searchable index attributes, and the encrypted data values are stored evenly across multiple servers by leveraging a distributed index framework. Based on this design, we show how to construct encrypted indexes, generate search tokens, and query parallelly to achieve efficient Boolean search. Moreover, these queries are not only limited to those initiated by the data owner but also by other authorized clients. Specifically, we further integrate a recent scheme to make the authorization of client's requests non-interactive. The data owner is not required to stay online to interact with the clients. We characterize the leakage profile and provide a formal security analysis to demonstrate that our system can guarantee data confidentiality and query privacy. To validate our protocol, we implement a system prototype and evaluate the efficiency of our construction experimentally. Through experimental results, we show the effectiveness of our protocol in term of data encryption time and Boolean query time.