Abstract
We will construct a perfectly hiding commitment in two rounds from any one-way permutation, which is a negation of this result that O(n/(log n)) rounds is the tight lower bound on the rounds complexity of perfectly hiding commitments from any one-way permutation. Based on our commitments, we will construct a computational zero-knowledge proof for any NP that achieves negligible error probability in 5 rounds of interaction, assuming only the existence of a one-way permutation.