Paper 2014/997 Original: eprint.iacr.org/2014/997 ↗
Constants Count: Practical Improvements to Oblivious RAM
Abstract
Oblivious RAM (ORAM) is a cryptographic primitive that hides memory access patterns as seen by untrusted storage. This paper proposes Ring ORAM, the most bandwidth-efficient ORAM scheme for the small client storage setting in both theory and practice. Ring ORAM is the first tree-based ORAM whose bandwidth is independent of the ORAM bucket size, a property that unlocks multiple performance improvements. First, Ring ORAM’s overall bandwidth is 2.3x to 4x better than Path ORAM, the prior-art scheme for small client storage. Second, if memory can perform simple untrusted computation, Ring ORAM achieves constant online bandwidth (~60x improvement over Path ORAM for practical parameters). As a case study, we show Ring ORAM speeds up program completion time in a secure processor by 1.5x relative to Path ORAM. On the theory side, Ring ORAM features a tighter and significantly simpler analysis than Path ORAM.
Metadata
- Available format(s)
PDF- Category
- Cryptographic protocols
- Publication info
- Preprint.
- History
- 2015-07-07: last updated
- 2014-12-18: published
- Short URL
- https://ia.cr/2014/997
- License
- https://creativecommons.org/licenses/by/4.0/
BibTeX
@misc{cryptoeprint:2014/997,
author = {Ling Ren and Christopher W. Fletcher and Albert Kwon and Emil Stefanov and Elaine Shi and Marten van Dijk and Srinivas Devadas},
title = {Constants Count: Practical Improvements to Oblivious RAM},
howpublished = {Cryptology {ePrint} Archive, Paper 2014/997},
year = {2014},
url = {https://eprint.iacr.org/2014/997}
}