ThinORAM: Towards Practical Oblivious Data Access in Fog Computing Environment

Oblivious RAM (ORAM) is important for applications that require hiding of access patterns. However, most of existing implementations of ORAM are very expensive, which are infeasible to be deployed in lightweight devices, likethe gateway devices as fog nodes. In this paper, we focus on how to apply the expensive ORAM to protect access pattern in lightweight devices and propose an ORAM scheme supporting thin-client, called “ThinORAM”, under non-colluding clouds. Our proposed scheme removes complicated computations in the client side and requires only $O$ (1) communication cost with a reasonable response time. We further show how to securely deploy ThinORAM in the fog computing environment to achieve oblivious data access with minimum client cost. Experiments show that our scheme can eliminate most of the client storage and reduce the cloud-cloud bandwidth by 2 ×, with 2 × faster response time, when compared to the best scheme that aims at reducing client side overheads.