arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2006.01418cs.CR
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闪电网络上的时间膨胀攻击

Time-Dilation Attacks on the Lightning Network

Antoine Riard, Gleb Naumenko

摘要:

闪电网络(LN)是一个广泛使用的支付渠道网络,可以实现更快,更便宜的比特币交易。在本文中,我们概述了攻击者可以从诚实的LN用户那里窃取资金的三种方式。这些攻击需要通过使受害者与网络隔离并延迟区块交付来延长受害者意识到新区块的时间。虽然我们的重点是LN,时间膨胀攻击可能与任何依赖于及时反应的第二层协议有关。根据我们的测量,目前有可能通过使一个节点遮挡短至2小时来窃取总信道容量。由于信任最小化的比特币轻客户端目前连接到数量非常有限的随机节点,因此只需运行500个Sybil节点,攻击者就可以吃掉47%的新部署的轻客户端(因此可以对它们进行攻击)。至于运行完整节点的受害者,由于它们通常被大型中心或服务提供商使用,攻击者可能会通过窃取其所有可用的流动性来证明更高的Eclipse攻击成本。此外,时间膨胀攻击既不需要访问哈希率,也不需要从受害者那里购买。因此,这类攻击是通过Eclipse攻击窃取资金的一种更实用的方式,而不是之前预期的双重支出。我们认为,简单的检测技术的基础上的慢块到达单独是无效的,实现更复杂的检测是不平凡的。我们认为,反Eclipse/反Sybil措施的组合是至关重要的,以减轻时间膨胀攻击。

英文摘要:

Lightning Network (LN) is a widely-used network of payment channels enabling faster and cheaper Bitcoin transactions. In this paper, we outline three ways an attacker can steal funds from honest LN users. The attacks require dilating the time for victims to become aware of new blocks by eclipsing (isolating) victims from the network and delaying block delivery. While our focus is on the LN, time-dilation attacks may be relevant to any second-layer protocol that relies on a timely reaction. According to our measurements, it is currently possible to steal the total channel capacity by keeping a node eclipsed for as little as 2 hours. Since trust-minimized Bitcoin light clients currently connect to a very limited number of random nodes, running just 500 Sybil nodes allows an attacker to Eclipse 47\% of newly deployed light clients (and hence prime them for an attack). As for the victims running a full node, since they are often used by large hubs or service providers, an attacker may justify the higher Eclipse attack cost by stealing all their available liquidity. In addition, time-dilation attacks neither require access to hashrate nor purchasing from a victim. Thus, this class of attacks is a more practical way of stealing funds via Eclipse attacks than previously anticipated double-spending. We argue that simple detection techniques based on the slow block arrival alone are not effective, and implementing more sophisticated detection is not trivial. We suggest that a combination of anti-Eclipse/anti-Sybil measures are crucial for mitigating time-dilation attacks.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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