A Rational Secret Sharing Scheme Based on Repeated Game

Rational player´s behavior in secret sharing schemes always determined by their expect payoff, under this scenario, they have not incentive to send secret share, this rational behavier makes secret sharing impossible. In order to force rational player to cooperate for achieving successful secret sharing, we propose a new rational secret sharing scheme based on repeated game, players interact repeatedly in several rounds, a rational player may be deterred from exploiting his short term advantage by the threat of Grim Trigger Strategy (GTS) that reduces his long term payoff, which enables the possibility of secret sharing among rational players. In this scheme, the secret shadow is selected by the player himself instead of being distributed by the dealer, and even the dealer cannot gain the player´s share. After analyzing, our scheme has higher safety and effectiveness, to better meet the application requirements.