A Rational Secret Sharing Scheme Against Coalition Based on Nash Equilibrium and Neighbor s Strategy

In order to prevent any arbitrary subsets of coalition in rational secret sharing, we propose a new oneway information transmission mechanism, every player in a rational secret sharing protocol only interacts with his around two players, which means his decision is strictly based on previous neighboring player's strategy. Combined with the punishment strategy of Maleka's scheme and payoff distribution principle in Game Theory, our scheme is capable of achieving Nash equilibrium and has the feature of anti-coalition. For the conspirators, getting the secret at the same time or in less than necessary iteration rounds is almost impossible. Without repeated involvement of the dealer, our scheme has the features of verifiability, anticoalition, and more meaningfully, superiority of approaching reality model by taking rational behavior into consideration.