AI 中文总结
本文针对XRP账本网络，提出边扩充策略提升其鲁棒性，对比重连策略发现该策略在少量新增边时即可实现更优鲁棒性，且拓扑相似性更接近原始网络。
AI 中文摘要
XRP账本允许其网络参与者在网络内选择一组可信对等节点（即唯一节点列表UNL），并与这些节点通信以就哪些交易应被纳入下一个账本状态达成共识。然而，其共识协议要求参与者的UNL之间存在显著重叠，且每个UNL内的节点需满足较高的共识阈值（例如80%）。因此，攻击者可通过攻击构成网络连接骨干的节点，将能够相互通信的可信参与者数量降至所需阈值以下，从而破坏该网络的共识过程。在本文中，我们基于对法定人数和网络鲁棒性的形式化定义，评估用于提升XRP账本现有拓扑鲁棒性的策略，并将其与现有研究中的第二种策略进行比较。我们提出的策略是一种边添加/扩充方法，其中基于不同的构造方式添加新边；第二种策略是一种重连或边替换方法，其中边的总数量保持不变但会被重新排列。对于每种策略，我们考虑两种不同情况：一种是所有节点都参与边的构造或重连过程，另一种是仅部分节点参与。我们的研究结果表明，与默认的XRP账本拓扑相比，使用扩充策略可实现鲁棒性的显著提升，且部分扩充策略在添加边数量较少时（例如每个节点添加三条边），其鲁棒性指标可达到或超过重连策略。此外，我们还发现，基于随机K-out的扩充策略在拓扑相似性上比重连策略更接近原始网络，该相似性通过Jaccard相似度进行衡量。
英文摘要
The XRP Ledger allows its network participants to select a set of trusted peers within the network (i.e., the Unique Node List (UNL)) and communicate with them to reach consensus on which transactions should be included in the next ledger state. However, its consensus protocol requires significant overlap among participants' UNLs, along with a high agreement threshold among the nodes within each UNL (e.g., 80\%). Consequently, an attacker could disrupt the consensus process in such a network by targeting the nodes that form the network's connectivity backbone and reducing the number of trusted participants that can communicate with one another below the required threshold. In this paper, we evaluate strategies to improve the robustness of the XRP Ledger's existing topology, as measured by our formal definitions of quorum and network robustness, and compare them to a second strategy from prior work. The strategy we present is an addition/augmentation approach, in which new edges are added based on different constructions. The second strategy is a rewiring or edge-replacement approach, in which the overall number of edges is preserved but they are rearranged. For each strategy, we consider two different cases: one in which all nodes participate in the edge construction or rewiring process, and another in which only a subset of nodes participates. Our findings demonstrate substantial improvements in robustness when augmentation strategies are used over the default XRP Ledger topology and show that some augmentation strategies achieve robustness metrics equal to or exceeding the rewiring strategy, even when the number of edges added is small (e.g., three edges per node). Additionally, we show that the random K-out-based augmentation strategy maintains higher topological similarity to the original network than rewiring, as measured by Jaccard similarity.
