Robust ORAM: Enhancing Availability, Confidentiality and Integrity

Oblivious RAM (ORAM) is a primitive for hiding storage access patterns in the context of software protection. With the trend of cloud computing, ORAM also has important applications in privacy-preserving cloud storage applications. Many ORAMs for cloud storage have been proposed to improve efficiency and security. However, data availability, data confidentiality, and data integrity have not been simultaneously addressed. In this paper, we formalize a new concept of ORAM called RORAM (Robust ORAM by enhancing availability, confidentiality and integrity), which can deal with these three challenges. Furthermore, RORAM not only can achieve a higher security level but also is more efficient compared with previous ORAMs by using linear network coding to reduce the client's computational cost of block encryption/decryption in every read/write operation in previous ORAMs. The security and complexity analyses show that RORAM is provably secure and highly lightweight.