Towards Practical Oblivious RAM

We take an important step forward in making Oblivious RAM (O-RAM) practical. We pro-pose an O-RAM construction achieving an amortized overhead of 20 ∼ 35X (for an O-RAMroughly 1 terabyte in size), about 63 times faster than the best existing scheme. On the theoreticfront, we propose a fundamentally novel technique for constructing Oblivious RAMs: specifi-cally, we partition a bigger O-RAM into smaller O-RAMs, and employ a background evictiontechnique to obliviously evict blocks from the client-side cache into a randomly assigned server-side partition. This novel technique is the key to achieving the gains in practical performance.