We show that the existence of a coin-flipping protocol safe against \emph{any} non-trivial constant bias (\eg $.499$) implies the existence of one-way functions. This improves upon a recent result of Haitner and Omri [FOCS '11], who proved this implication for protocols with bias $\frac{\sqrt2 -1}2 - o(1) \approx .207$. Unlike the result of Haitner and Omri, our result also holds for \emph{weak} coin-flipping protocols.

中文翻译：

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\ emph {Any}常量偏差的硬币翻转表示单向函数

我们表明，存在一种针对\ emph {any}非平凡的恒定偏差（例如\ .499 $）安全的硬币翻转协议，意味着存在单向函数。这是基于Haitner和Omri [FOCS '11]的最新结果得出的，他们的结果证明了对偏差$ \ frac {\ sqrt2 -1} 2-o（1）\约.207 $的协议的影响。与Haitner和Omri的结果不同，我们的结果也适用于\ emph {weak}掷硬币协议。