A proof of the security of the Bitcoin protocol is made rigorous, and simplified in certain parts. A computational model in which an adversary can delay transmission of blocks by time $Δ$ is considered. The protocol is generalized to allow blocks of different scores and a proof within this more general model is presented. An approach used in a previous paper that used random walk theory is shown through a counterexample to be incorrect; an approach involving a punctured block arrival process is shown to remedy this error. Thus, it is proven that with probability one, the Bitcoin protocol will have infinitely many honest blocks so long as the fully-delayed honest mining rate exceeds the adversary mining rate.

翻译：本文对比特币协议的安全性证明进行了严格化处理，并在某些部分进行了简化。研究考虑了一个计算模型，其中对手可将区块传输延迟时间$Δ$。该协议被推广至允许不同权重的区块，并在此更广义模型中给出了证明。通过反例指出先前论文中采用随机游走理论的方法存在错误；采用带孔洞的区块到达过程的方法被证明可修正此错误。由此严格证明：只要完全延迟后的诚实挖矿率超过对手挖矿率，比特币协议将以概率1拥有无限多个诚实区块。