Paper 2013/257

Secure two-party computation: a visual way

Paolo D'Arco and Roberto De Prisco

Abstract

In this paper we propose a novel method for performing secure two-party computation. By merging together in a suitable way two beautiful ideas of the 80's and the 90's, Yao's garbled circuit construction and Naor and Shamir's visual cryptography, respectively, we enable Alice and Bob to securely evaluate a function $f(\cdot,\cdot)$ of their inputs, $x$ and $y$, through a {\em pure physical} process. Indeed, once Alice has prepared a set of properly constructed transparencies, Bob computes the function value $f(x,y)$ by applying a sequence of simple steps which require the use of a pair of scissors, superposing transparencies, and the human visual system. A crypto-device for the function evaluation process is not needed any more.