Generalization of Socio-Rational Secret Sharing with a New Utility Function

Abstract—Rational secret sharing shows that, in a setting with rational players, secret sharing and multiparty computation are only possible if the actual secret reconstruction round remains unknown to the parties. However, in socio-rational secret sharing, players not only are rational but also are foresighted. In other words, the secret sharing game is repeatedly played and players are only invited to each game based on their reputation. This social reinforcement stimulates the players to be cooperative. As our contribution, we revisit socio-rational secret sharing and generalize it from the utility computation aspect. We show that, in (2, 2) and (t, n) socio-rational secret sharing, it is always in players ’ best interest to cooperate using our new utility function