An efficient compiler from ∑-protocol to 2-move deniable zero-knowledge

Abstract

Pass showed a 2-move deniable zero-knowledge argument scheme for any NP language in the random oracle model at Crypto 2003. However, this scheme is very inefficient because it relies on the cut and choose paradigm (via straight-line witness extractable technique). In this paper, we propose a very efficient compiler that transforms any ∑-protocol to a 2-move deniable zero-knowledge argument scheme in the random oracle model, which is also a resettable zero-knowledge and resettably-sound argument of knowledge. Since there is no essential loss of efficiency in our transform, we can obtain a very efficient undeniable signature scheme and a very efficient deniable authentication scheme. © Springer-Verlag Berlin Heidelberg 2006.