Faster Secure Two-Party Computation with Less Memory

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 imple-mentations. Our improvements include (1) the first multi-threaded implementation of the base oblivious transfers re-sulting in a speedup of a factor of two, (2) techniques for minimizing the memory footprint during oblivious trans-fer extensions and processing of circuits, (3) compilation of sub-circuits into files, and (4) caching of circuit descrip-tions and network packets. We implement improved cir-cuit 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 on-line time