1 research outputs found
H-ORAM: A Cacheable ORAM Interface for Efficient I/O Accesses
Oblivious RAM (ORAM) is an effective security primitive to prevent access pattern
leakage. By adding redundant memory accesses, ORAM prevents attackers from revealing the
patterns in the access sequences. However, ORAM tends to introduce a huge degradation on the
performance. With growing address space to be protected, ORAM has to store the majority of
data in the lower level storage, which further degrades the system performance.
In this paper, we propose Hybrid ORAM (H-ORAM), a novel ORAM primitive to address
large performance degradation when overflowing the user data to storage. H-ORAM consists of a
batch scheduling scheme for enhancing the memory bandwidth usage, and a novel ORAM
interface that returns data without waiting for the I/O access each time. We evaluate H-ORAM on
a real machine implementation. The experimental results show that that H-ORAM outperforms the
state-of-the-art Path ORAM by 19.8x for a small data set and 22.9x for a large data set