Utility Dependence in Correct and Fair Rational Secret Sharing

Achieving Correctness in Fair Rational Secret Sharing

Purely Rational Secret Sharing

Rational secret sharing is a fundamental primitive at the intersection of cryptography and game theory. In essence, a dealer wishes to engineer a communication game that, when rationally played, guarantees that each of the players learns the dealer’s secret. Yet, all solutions so far were quite inefficient and relied on the players’ beliefs and not just on their rationality. After providing a m...

Rational Secret Sharing, Revisited

We consider the problem of secret sharing among n rational players. This problem was introduced by Halpern and Teague (STOC 2004), who claim that a solution is impossible for n = 2 but show a solution for the case n ≥ 3. Contrary to their claim, we show a protocol for rational secret sharing among n = 2 players; our protocol extends to the case n ≥ 3, where it is simpler than the Halpern-Teague...

Fair secret reconstruction in (t, n) secret sharing

In Shamir’s (t, n) threshold secret sharing scheme, one secret s is divided into n shares by a dealer and all shares are shared among n shareholders, such that knowing t or more than t shares can reconstruct this secret; but knowing fewer than t shares cannot reveal any information about the secret s. The secret reconstruction phase in Shamir’s (t, n) threshold secret sharing is very simple and...

Rational Secret Sharing without Broadcast

We use the concept of rational secret sharing, which was initially introduced by Halpern and Teague [2], where players’ preferences are that they prefer to learn the secret than not, and moreover they prefer that as few others learn the secret as possible. This paper is an attempt to introduce a rational secret sharing scheme which defers from previous RSS schemes in that this scheme does not r...