POSTER: Oblivious Access System on Decentralized Database over Parallel Smart Contract Model

Abstract

Data stored on centralized cloud servers may have some risks. Moreover, it may leak the data access pattern when accessing data on cloud servers. Oblivious RAM (ORAM) is a candidate solution to hide the data access pattern, but it inherently induces some overheads of accessing data. In this paper, we address the issues above, and propose the oblivious access system on decentralized database over parallel smart contract model. The proposed system can slightly reduce the overhead of ORAM and overcome the problem from centralized servers. The main techniques are to use parallel smart contract model to improve the performance of smart contract execution and garbled circuit to reduce the cost of communication.