Paper 2008/533
Collusion-Free Multiparty Computation in the Mediated Model
Jonathan Katz and Yehuda Lindell
Abstract
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.
Metadata
- Available format(s)
- Category
- Cryptographic protocols
- Publication info
- Published elsewhere. Unknown where it was published
- Keywords
- secure computation
- Contact author(s)
- jkatz @ cs umd edu
- History
- 2008-12-19: received
- Short URL
- https://ia.cr/2008/533
- License
-
CC BY