R&D: Loco-Store, Locality-based Oblivious Storage

IEEE Transactions on Dependable and Secure Computing has published an article written by Wenlong Tian, School of Computer and Science, University of South China, 34706 Hengyang, HuNan China, Ruixuan Li, School of Computer Science and Technology, Huazhong University of Science and Technology, Wuhan, HuBei China 430074, Zhiyong Xu, the Math and Computer Science, Suffolk University, Boston, MA, USA, and Weijun Xiao, Electrical and Computer Engineering, Virginia Commonwealth University, Richmond, VA 23284, USA.

Abstract: “With the growing popularity of cloud storage, how to prevent information leakage from cloud access patterns attracts great attention. Oblivious RAM is proposed for this purpose. It is designed for the memory system, and most existing work focused on improving performance in the main memory. Recently, ORAM has been extended to the cloud environment, and it is called Oblivious Data Storage. TaoStore, the state-of-the-art oblivious data storage system, integrates the ORAM technology with synchronous I/O technology to reduce the mean response time. As we observed, there is a strong locality existing in user accesses. However, existing Oblivious Storage research did not consider this. In this paper, we propose Loco-Store, an oblivious data storage. In Loco-Store, we design a novel stash controller scheme that can dynamically group relevant blocks during the oblivious I/O processes. We also propose a locality-based eviction algorithm to keep the security guarantee. The theoretical proof proves that our scheme keeps the security definition of ORAM. Finally, we implement a prototype and conduct extensive experiments on real-world datasets. The results show that Loco-Store can save the network bandwidth consumption up to 39.19%, and reduce the overall access time by 26.17%.“