论文标题
POA集团中的Frontrunning Block攻击：一个案例研究
Frontrunning Block Attack in PoA Clique: A Case Study
论文作者
论文摘要
作为分散财务（DEFI）的基本技术，区块链维持分布式公平分类帐的能力受到操纵/交易订单的操纵威胁。在本文中，我们提出了针对基于集团的权威证明（POA）算法的领域攻击。我们的攻击可以通过打破适当的领导者选择顺序从诚实的内向密封剂中挡住。通过伪造优先级参数（\ textit {困难}和\ textit {delay time}），恶意的封闭式密封剂始终可以成功地占据领导者位置并产生可能包含有利可图的交易的有利块。通常，我们将攻击应用于成熟的集团发动机项目HPB（\ $ 3,058,901，截至2022年4月）。实验结果证明了有效性和可行性。然后，我们进一步建议修复，以使身份检查有效。我们的调查和建议已提交给其官方团队，并获得了批准。我们认为，这项工作至少可以作为集团变体的警告案例，以避免重复这些设计错误。
As a fundamental technology of decentralized finance (DeFi), blockchain's ability to maintain a distributed fair ledger is threatened by manipulation of block/transaction order. In this paper, we propose a frontrunning block attack against the Clique-based Proof of Authority (PoA) algorithms. Our attack can frontrun blocks from honest in-turn sealers by breaking the proper order of leader selection. By falsifying the priority parameters (both \textit{difficulty} and \textit{delay time}), a malicious out-of-turn sealer can always successfully occupy the leader position and produce advantageous blocks that may contain profitable transactions. As a typical instance, we apply our attack to a mature Clique-engined project, HPB (\$3,058,901, as of April 2022). Experimental results demonstrate the effectiveness and feasibility. Then, we further recommend fixes that make identity checks effective. Our investigation and suggestion have been submitted to its official team and got their approval. We believe this work can act as, at least, a warning case for Clique variants to avoid repeating these design mistakes.
