Serial composition of quantum coin-flipping, and bounds on cheat detection for bit-commitment
Quantum Physics
2007-05-23 v2
Abstract
Quantum protocols for coin-flipping can be composed in series in such a way that a cheating party gains no extra advantage from using entanglement between different rounds. This composition principle applies to coin-flipping protocols with cheat sensitivity as well, and is used to derive two results: There are no quantum strong coin-flipping protocols with cheat sensitivity that is linear in the bias (or bit-commitment protocols with linear cheat detection) because these can be composed to produce strong coin-flipping with arbitrarily small bias. On the other hand, it appears that quadratic cheat detection cannot be composed in series to obtain even weak coin-flipping with arbitrarily small bias.
Cite
@article{arxiv.quant-ph/0311165,
title = {Serial composition of quantum coin-flipping, and bounds on cheat detection for bit-commitment},
author = {Carlos Mochon},
journal= {arXiv preprint arXiv:quant-ph/0311165},
year = {2007}
}
Comments
7 pages, REVTeX 4 (minor corrections in v2)