A Universally-composable Secure Non-interactive Commitment Scheme
The commitment scheme is one of the most fundamental components in cryptography,and is the basis of many crypto-graphic protocols,such as zero-knowledge proof and secure multi-party computing protocols.Universally composability(UC)is of great significance in designing secure protocols,if a protocol is proven secure in the UC framework,it still maintains security even if it is executed concurrently with arbitrary(even insecure)protocols.Several current efficient UC commitment schemes are all interactive protocols,and non-interactive UC commitments have high computational cost and communication complexity of the protocol.Aiming at solving this problem,an efficient UC-secure non-interactive commitment scheme in the common refer-ence string model is proposed.The key design idea of universally composable commitments are to achieve extractability and equivocability at the same time.A CCA2-secure encryption scheme is used to achieve extractability in the commitment phase.A non-interactive zero-knowledge proof is used in the decommitment phase,and a dual-model commitment scheme is utilized to maintain protocol equivocability.The proposed protocol reduces the multi-round communication to one round in the open phase,achieving the non-interactivity.Compared with the existing non-interactive commitment scheme,the cost of computation and communication are greatly reduced,and the efficiency of the protocol is improved.
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维普
