Payment channel networks (PCN) enable scalable blockchain transactions without fundamentally changing the underlying distributed ledger algorithm. However, routing a payment via multiple channels in a PCN requires locking collateral for potentially long periods of time. Adversaries can abuse this mechanism to conduct denial-of-service attacks. Previous work focused on source routing, which is unlikely to remain a viable routing approach as these networks grow. In this work, we examine the effectiveness of attacks in PCNs that use routing algorithms based on local knowledge, where compromised intermediate nodes can delay or drop transactions to create denial-of-service. We focus on SpeedyMurmurs as a representative of such protocols. We identify two attacker node selection strategies; one based on the position in the routing tree, and the other on betweenness centrality. Our simulation-driven study shows that while they are both effective, the centrality-based attack approaches near-optimal effectiveness. We also show that the attacks are ineffective in less centralized networks and discuss incentives for the participants in PCNs to create less centralized topologies through the payment channels they establish among themselves.
翻译:支付渠道网络(PCN)在不从根本上改变基本的分布分类账算法的情况下,使可扩展的链条交易得以扩展。然而,通过多渠道在多氯化萘中进行支付需要长期锁定抵押品。对口者可以滥用这一机制进行拒绝服务袭击。以前的工作重点是源路径,随着这些网络的成长,这种路径不太可能继续成为可行的路径路径方法。在这项工作中,我们审查了使用基于当地知识的路径算法的多氯化萘袭击的有效性,在这些路径算法中,受损的中间节点可以延迟或减少交易,从而造成服务中断。我们注重SpeedyMurmurs作为这种协议的代表。我们确定了两个攻击者节点选择战略;我们确定了两个攻击者节点选择战略;一个基于在路边树上的位置,另一个基于中间中心。我们的模拟驱动研究表明,虽然这些攻击方法都有效,但以中心点为基础的攻击方法接近最佳效果。我们还表明,攻击在较不集中的网络中是无效的,我们讨论鼓励PCN参与者通过它们自己建立的付款渠道创造较集中的表层。