In this work, we present the first practical protocols for evaluating RAM programs with security against malicious adversaries. A useful efficiency measure is to divide the cost of malicious-secure evaluation of $f$ by the cost of semi-honest-secure evaluation of $f$. Our RAM protocols achieve ratios matching the state of the art for circuit-based 2PC. For statistical security $2^{-s}$, our protocol without preprocessing achieves a ratio of $s$; our online-offline protocol has a pre-processing phase and achieves online ratio $\sim 2 s / \log T$, where $T$ is the total execution time of the RAM program.
To summarize, our solutions show that the ``extra overhead" of obtaining malicious security for RAM programs (beyond what is needed for circuits) is minimal and does not grow with the running time of the program.
Category / Keywords: cryptographic protocols / secure computation, oblivious ram Original Publication (with major differences): IACR-EUROCRYPT-2015 Date: received 28 Sep 2014, last revised 30 Jan 2015 Contact author: rosulekm at eecs oregonstate edu Available format(s): PDF | BibTeX Citation Note: Clarified references to SCVM Version: 20150130:191311 (All versions of this report) Short URL: ia.cr/2014/759 Discussion forum: Show discussion | Start new discussion