Leakage-resilient coin tossing
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Goldwasser_Leakage-resilient.pdf
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Author(s)
Boyle, Elette
Goldwasser, Shafi
Date Issued
January 2011
Journal
Distributed Computing
Publisher
Spring Berlin/Heidelberg
Citation
Boyle, Elette, Shafi Goldwasser, and Yael Tauman Kalai. “Leakage-Resilient Coin Tossing.” Distributed Computing. Ed. David Peleg. Vol. 6950. Berlin, Heidelberg: Springer Berlin Heidelberg, 2011. 181-196. © 2011 Springer
Version
Final published version
Abstract
The ability to collectively toss a common coin among n parties
in the presence of faults is an important primitive in the arsenal of
randomized distributed protocols. In the case of dishonest majority, it
was shown to be impossible to achieve less than 1
r bias in O(r) rounds
(Cleve STOC ’86). In the case of honest majority, in contrast, unconditionally
secure O(1)-round protocols for generating common unbiased
coins follow from general completeness theorems on multi-party secure
protocols in the secure channels model (e.g., BGW, CCD STOC ’88).
However, in the O(1)-round protocols with honest majority, parties
generate and hold secret values which are assumed to be perfectly hidden
from malicious parties: an assumption which is crucial to proving the
resulting common coin is unbiased. This assumption unfortunately does
not seem to hold in practice, as attackers can launch side-channel attacks
on the local state of honest parties and leak information on their secrets.
In this work, we present an O(1)-round protocol for collectively generating
an unbiased common coin, in the presence of leakage on the local
state of the honest parties. We tolerate t ≤ ( 1
3
− )n computationallyunbounded
Byzantine faults and in addition a Ω(1)-fraction leakage on
each (honest) party’s secret state. Our results hold in the memory leakage
model (of Akavia, Goldwasser, Vaikuntanathan ’08) adapted to the
distributed setting.
Additional contributions of our work are the tools we introduce to
achieve the collective coin toss: a procedure for disjoint committee election,
and leakage-resilient verifiable secret sharing.
Description
Proceedings 25th International Symposium, DISC 2011, Rome, Italy, September 20-22, 2011.
MIT Department
Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
Terms of Use
Creative Commons Attribution-Noncommercial-Share Alike 3.0
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DOI of Published Version
https://doi.org/10.1007/978-3-642-24100-0_16
