Paper 2018/005
Simple and Efficient Two-Server ORAM
Xiao Wang and Dov Gordon and Jonathan Katz
Abstract
We show a protocol for two-server oblivious RAM (ORAM) that is simpler and more efficient than the best prior work. Our construction combines any tree-based ORAM with an extension of a two-server private information retrieval scheme by Boyle et al., and is able to avoid recursion and thus use only one round of interaction. In addition, our scheme has a very cheap initialization phase, making it well suited for applications to RAM-based secure computation. A practical instantiation of our protocol has excellent concrete parameters: for storing an $N$-element array of arbitrary size data blocks with statistical security parameter $\lambda$, the servers each store $4N$ encrypted blocks, the client stores $\lambda+2 \log N$ blocks, and the total communication per logical access is roughly $10\log N$ encrypted blocks.
Metadata
- Available format(s)
- Category
- Cryptographic protocols
- Publication info
- Preprint. MINOR revision.
- Keywords
- ORAMsingle-roundmulti-party computationRAM model
- Contact author(s)
- wangxiao @ cs umd edu
- History
- 2018-09-05: last of 3 revisions
- 2018-01-02: received
- See all versions
- Short URL
- https://ia.cr/2018/005
- License
-
CC BY