IACR News item: 29 September 2014
Arash Afshar, Zhangxiang Hu, Payman Mohassel, Mike Rosulek
ePrint ReportIn 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.
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