An Efficient Protocol for the Commit-Prove-Fair-Open functionality.
Ou Ruan, Cai Fu, Guohua Cui · IACR Cryptology ePrint Archive · 2011
Commit-Prove-Fair-Open functionality Ou Ruan , Cai Fu a,* , Guohua Cui a a College of Compute Science & Technology, Huazhong University of Science & Technology, Wuhan, China, 430074 b College of Compute Science & Technology, Hubei University of Technology, Wuhan, China, 430068 [email protected], [email protected],[email protected] *:Corresponding author: Cai Fu , [email protected], [email protected] Research supported in part by the National Natural Science Funds of China(60903175) Abstract. In TCC 2006, Garay et al. introduced the notion of commit-prove-fair-open functionality in order to achieve what they called resource of secure multi-party computation(MPC) with corrupted majority. The protocol realizing this notion of fairness follows the gradual release approach and, further, it can be proven secure in the simulation paradigm and enjoys composition properties. In this paper, we show a more efficient resource-fair protocol of FCPFO based on a new variant of Garay et al. time-lines and simplified Camenisch-Shoup(sCS) commitment,whose communication and computation complexity are less than 1/5 of Garay et al. construction. In addition, our new protocol allows commitment to value 0, which is not possible in the plain Garay et al. construction.