Many cryptocurrencies including Bitcoin are susceptible to a so-called double-spend attack, where someone dishonestly attempts to reverse a recently confirmed transaction. The duration and likelihood of success of such an attack depends on the recency of the transaction and the computational power of the attacker, and these can be related to the distribution of time for counts from one Poisson process to exceed counts from another by some desired amount. We derive an exact expression for this distribution and show how it can be used to obtain efficient simulation estimators. We also give closed-form analytic approximations and illustrate their accuracy.

中文翻译：

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区块链双花攻击持续时间

包括比特币在内的许多加密货币都容易受到所谓的双花攻击，即有人不诚实地试图撤销最近确认的交易。这种攻击的持续时间和成功的可能性取决于交易的新近程度和攻击者的计算能力，这些可能与一个泊松过程的计数超过另一个泊松过程的计数的时间分布有关。 . 我们推导出此分布的精确表达式，并展示如何使用它来获得有效的模拟估计器。我们还给出了封闭式解析近似并说明了它们的准确性。