The rational secret sharing cannot be realized in the case of being played only once, and some punishments in the one-time rational secret sharing schemes turn out to be empty threats. In this paper, after modeling 2-out-of-2 rational secret sharing based on Bayesian game and considering different classes of protocol parties, we propose a 2-out-of-2 secret sharing scheme to solve cooperative problem of a rational secret sharing scheme being played only once. Moreover, we prove that the strategy is a perfect Bayesian equilibrium, adopted only by the parties in their decision-making according to their belief system （denoted by the probability distribution） and Bayes rule, without requiring simultaneous channels.
To resolve the problem of quantitative analysis in hybrid cloud,a quantitative analysis method,which is based on the security entropy,is proposed.Firstly,according to the information theory,the security entropy is put forward to calculate the uncertainty of the system' s determinations on the irregular access behaviors.Secondly,based on the security entropy,security theorems of hybrid cloud are defined.Finally,typical access control models are analyzed by the method,the method's practicability is validated,and security and applicability of these models are compared.Simulation results prove that the proposed method is suitable for the security quantitative analysis of the access control model and evaluation to access control capability in hybrid cloud.
