CryptoDB

Paper: Improving the Round Complexity of 'Round-Optimal' VSS

Authors: Jonathan Katz Chiu-Yuen Koo Ranjit Kumaresan URL: http://eprint.iacr.org/2007/358 Search ePrint Search Google We revisit the following question: what is the optimal round complexity of verifiable secret sharing~(VSS)? We focus here on the case of perfectly-secure VSS where the number of corrupted parties $t$ satisfies $t < n/3$, with $n$ being the total number of parties. Work of Gennaro et al. (STOC~2001) and Fitzi et al. (TCC~2006) shows that, assuming a broadcast channel, 3~rounds are necessary and sufficient for efficient VSS. The efficient 3-round protocol of Fitzi et al., however, treats the broadcast channel as being available for free'' and does not attempt to minimize its usage. As argued previously by the authors, this approach leads to poor round complexity when protocols are compiled for a point-to-point network. We show here a VSS protocol that is simultaneously optimal in terms of both the number of rounds and the number of invocations of broadcast. Our protocol also has a certain 2-level sharing'' property that makes it useful for constructing protocols for general secure computation.
BibTeX
@misc{eprint-2007-13638,
title={Improving the Round Complexity of 'Round-Optimal' VSS},
booktitle={IACR Eprint archive},
keywords={cryptographic protocols / VSS, secure multiparty computation},
url={http://eprint.iacr.org/2007/358},
note={ jkatz@cs.umd.edu 13766 received 10 Sep 2007},
author={Jonathan Katz and Chiu-Yuen Koo and Ranjit Kumaresan},
year=2007
}