The work reported here has been cited in the literature already in 1988. However , no version of this work has ever appeared before. However, these works have also advantages over ours. Theoretical Computer Science 84, 1991. Each can be formalized in one of two ways, a weak and a strong, depending on whether or not we restrict the adversary involved to polynomial time.
Conviction is about soundness.
In their terminology, our four round protocols would be four move or two round protocols. CZK argument 4 Trapdoor perm. G. Brassard, C. Cr' epeau and M. Yung. Constant round perfect zero knowledge computationally convincing protocols . Theoretical Computer Science, Vol.