with an Honest Minority and a Rational Majority
of Computer Science, The Herzliya Interdisciplinary
July 6, 2009 (Monday)
4:30p.m. - 5:30 p.m.
Rm. 121, Ho Sin Hang Engineering Building, CUHK
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
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