A Distributed Rational Secret Sharing Scheme with Hybrid Preference Model

In traditional secret sharing schemes, players are either honest or malicious. An honest player follows the protocol perfectly but a malicious player always deviate from the protocol. However, players behavior is selfish and they follow the protocol only if their expected utility is satisfied in rational secret sharing scheme. In that sense, rational secret sharing has more applicability. In the existence of rational secret sharing schemes, the preference models only focus on immediate interests or long-term interests, and the secrets distributions rely on the dealer. But such dealer may not exist in some special settings. After analyzing the traditional distributed secret sharing schemes, a general formalization of distributed rational secret sharing scheme is proposed. In our setting, a new hybrid preference model which simultaneously considers the immediate interests and the long-term interests of rational participants is discussed. Meanwhile, combining with the strategy-proof mechanisms of mechanism design theory, the bargaining reputation mechanism is designed with the incentive compatibility, which is effectively to restrict the behavior of the rational players, so that a fair (t,n) (t,n≥2) distributed rational secret sharing scheme is realized. Finally, some advantages of our scheme are showed by comparing with current rational secret sharing schemes in communication channel types, the requirement of on-line or off-line dealer, universality and the rational players preference model.