Faster secure two-party computation with less memory

Abstract

Secure two-party computation is used as the basis for a large variety of privacy-preserving protocols, but often concerns about the low performance hinder the move away from non-private solutions. In this paper we present an improved implementation of Yao's garbled circuit protocol in the semi-honest adversaries setting which is up to 10 times faster than previous implementations. Our improvements include (1) the first multi-threaded implementation of the base oblivious transfers resulting in a speedup of a factor of two, (2) techniques for minimizing the memory footprint during oblivious transfer extensions and processing of circuits, (3) compilation of sub-circuits into files, and (4) caching of circuit descriptions and network packets. We implement improved circuit building blocks from the literature and present for the first time performance results for secure evaluation of the ultra-lightweight block cipher PRESENT within 7 ms online time.