Concurrent Non-Malleable Commitments and More in 3 Rounds

摘要: The round complexity of commitment schemes secure against man-in-the-middle attacks has been the focus extensive research for about 25 years. recent breakthrough Goyal et al. [22] showed that 3 rounds are sufficient one-left, one-right non-malleable commitments. This result matches a lower bound ofi¾?[41]. state affairs leaves still open intriguing problem constructing 3-round concurrent schemes. In this paper we solve above by showing how to transform any one-left scheme with some extractability property in scheme. Our makes use leveraging and when instantiated construction ofi¾?[22] gives from one-way permutations w.r.t. subexponential-time adversaries. We also show arguments knowledge identification attacks.