Abstract :

I will present a simple protocol for secret reconstruction in any threshold secret sharing scheme, and argue 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. The protocol only requires a standard (synchronous) broadcast channel, and tolerates arbitrary deviations (including early stopping and 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.

Joint work with Shien Jin Ong, David Parkes and Salil Vadhan.

Biography :

Dr. Alon Rosen is a faculty member in the School of Computer Science at the Herzliya Interdisciplinary Center. Before that he spent two years as a postdoc. in the Cryptography Group of MIT's Computer Science and AI Lab, and two years as a postdoc in the Center for Research on Computation and Society at Harvard's department of Electrical Engineering and Computer Science. He received his Ph.D. at the Weizmann Institute of Science, under the supervision of Oded Goldreich and Moni Naor. His research interest are Cryptography and Computational Complexity.