Optimal transport layer for secure computation

Abstract

Although significantly improved, the performance of secure two-party computation (2PC) is still prohibitive for practical systems. Contrary to common belief that bandwidth is the remaining bottleneck for 2PC implementation, we show that the network is under-utilised due to the use of standard TCP sockets. Nevertheless, using other sockets is non-trivial: the developers of secure computation need to integrate them into the operating systems, which is a challenging task even for systems experts. To resolve the efficiency barrier of 2PC, we develop a framework, we call Transputation, which automates the integration of transport layer sockets into 2PC implementations. Transputation is the first tool which enables developers of 2PC protocols to easily identify and use the optimal transport layer protocol for the given computation task and network conditions. We integrate selected transport layer protocols into Transputation and evaluate the performance for a number of computational tasks. As a highlight, even a general purpose transport layer protocol, such as SABUL, improves the run-time of 2PC over TCP on EU-Australia connection for circuits with > 106 Boolean gates by a factor of 8. To enable evaluations of 2PC implementations in real life setups in the Internet we setup a distributed testbed.The testbed provides automated generation of network scenarios and runs evaluations of 2PC implementations. We evaluate Transputation on in different network setups and report on our experimental results in this work.