Evaluation of Memory Access Pattern Protection in a Practical Setting

Oblivious RAM schemes were proposed to protect software on un- trusted systems. However their huge overhead encumbers their practical deploy- ment. Recently, we proposed a new protection scheme using history of accesses. However, only the concept of the scheme was presented, and several issues were unclear for its implementation. In this paper, we propose a new instance of the scheme, which can be implemented with only software with less overhead than the previous instance. We also consider three attack scenarios and propose coun- termeasures. We implement the scheme with countermeasure and show that our scheme only requires 0.125(s) to write 1MB data.