International Association for Cryptologic Research

International Association
for Cryptologic Research

CryptoDB

David C. Parkes

Publications

Year
Venue
Title
2009
TCC
2008
EPRINT
Fairness with an Honest Minority and a Rational Majority
We provide a simple protocol for secret reconstruction in any threshold secret sharing scheme, and prove that it is fair when executed with many rational parties together with a small minority of honest parties. That is, all parties will learn the secret with high probability when the honest parties follow the protocol and the rational parties act in their own self-interest (as captured by the notion of a Bayesian subgame perfect equilibrium). The protocol only requires a standard (synchronous) broadcast channel, and tolerates fail-stop deviations (i.e. early stopping, but not incorrectly computed messages). Previous protocols for this problem in the cryptographic or economic models have either required an honest majority, used strong communication channels that enable simultaneous exchange of information, or settled for approximate notions of security/equilibria.

Coauthors

Shien Jin Ong (2)
Alon Rosen (2)
Salil P. Vadhan (2)