## CryptoDB

### Paper: Collusion-Free Multiparty Computation in the Mediated Model

Authors: Jonathan Katz Yehuda Lindell URL: http://eprint.iacr.org/2008/533 Search ePrint Search Google Collusion-free protocols prevent subliminal communication (i.e., covert channels) between parties running the protocol. In the standard communication model (and assuming the existence of one-way functions), protocols satisfying any reasonable degree of privacy cannot be collusion-free. To circumvent this impossibility result, Alwen et al. recently suggested the mediated model where all communication passes through a mediator; the goal is to design protocols where collusion-freeness is guaranteed as long as the mediator is honest, while standard security guarantees continue to hold if the mediator is dishonest. In this model, they gave constructions of collusion-free protocols for commitments and zero-knowledge proofs in the two-party setting. We strengthen the definition of Alwen et al. in several ways, and resolve the key open questions in this area by showing a collusion-free protocol (in the mediated model) for computing any multi-party functionality.
##### BibTeX
@misc{eprint-2008-18107,
title={Collusion-Free Multiparty Computation in the Mediated Model},
booktitle={IACR Eprint archive},
keywords={cryptographic protocols / secure computation},
url={http://eprint.iacr.org/2008/533},
note={ jkatz@cs.umd.edu 14232 received 19 Dec 2008},
author={Jonathan Katz and Yehuda Lindell},
year=2008
}