抗合谋理性多秘密共享方案

Collusion-free Rational Multi-secret Sharing Scheme

提出了一种可抗合谋的理性多秘密共享方案。分析了成员合谋行为及防范对策,设计了可计算防合谋均衡方法,构建了预防参与者合谋的博弈模型,使得参与者所采取的策略满足可计算防合谋均衡,合谋成员不清楚当前轮是真秘密所在轮,还是检验参与者诚实度的测试轮,参与者采取合谋策略的期望收益没有遵守算法的收益大,因此,理性的参与者没有动机合谋攻击。另外,在方案中分发者不用为参与者分配秘密份额,在秘密重构阶段,无需可信者参与,也没有利用安全多方计算。最终,每位参与者可以得到多个秘密。解决了参与者合谋问题及理性单秘密共享效率低下的问题。

A collusion-free scheme for rational multi-secret sharing was proposed. Collusive behavior and preventive measures were analyzed. The coalition-proof model and algorithm were developed to make the participants＇ strategies satisfy computational coalition-proof equilibrium. The participants do not know whether the current round is a test round. Rational players can not gain more by coalition, so rational players have no incentive to collude in the protocol. In addition, the dealer doesn＇t need to distribute a secret share among the participants,and the scheme assumes neither the availability of a trusted party nor multi-party computations in the secret reconstruction phase. Finally, every player can obtain multi-secret fairly. The scheme is collusion-free and avoids the inefficiency of the rational single secret sharing scheme.