Unconditionally Secure Rational Secret Sharing in Standard Communication Networks
Rational secret sharing protocols in both the two-party and multi-party settings are proposed. These protocols are built in standard communication networks and with unconditional security. Namely, the protocols run over standard point-to-point networks without requiring physical assumptions or simultaneous channels, and even a computationally unbounded player cannot gain more than ? by deviating from the protocol. More precisely, for the 2-out-of-2 protocol the ? is a negligible function in the size of the secret, which is caused by the information-theoretic MACs used for authentication.