几种典型区块链共识机制的安全性分析

区块链技术源于比特币的出现，随着比特币和其他数字货币在金融市场的火爆，区块链技术得到了各界的广泛关注。共识机制是区块链技术的核心，区块链上的账本和数据都是共识机制的产物，一旦共识机制的安全性出现问题，区块链的可用性和信用度都将受到严重的打击。本文从共识机制的安全性出发，首先介绍区块链和共识机制的概念，然后对3种典型的区块链共识机制进行对比分析：通过逐一研究针对3种共识机制的攻击方法，对它们的一致性和敌手模型进行对比。最后，指出了目前区块链共识机制安全性分析上的局限性，并明确了未来研究共识机制安全性的方向。

Safety Analysis of Three Classic Blockchain Consensus Mechanisms

Blockchain technology originated from the emergence of bitcoin. With the popularity of bitcoin and other digital currencies in the financial market, blockchain technology has attracted wide attention from all circles. The consensus mechanism is the core of blockchain technology, and the ledger and data on the blockchain are the products of the consensus mechanism. Once the safety of the consensus mechanism is in question, the availability and credibility of blockchain will be seriously hit. Starting from the security of the consensus mechanism, this paper first introduces the concepts of blockchain and consensus mechanism, and then makes a comparative analysis of three classic blockchain consensus mechanisms. By studying the attack methods of the three consensus mechanisms one by one, their consistency and adversary models are compared. Finally, the limitations of current consensus mechanism safety analysis are pointed out, and the direction of future research on consensus mechanism safety is determined.