标题： 在区块链制裁下的规避 显示英文标题

标题： Evasion Under Blockchain Sanctions

摘要： 对区块链地址实施制裁已成为应对恶意活动的常见监管措施。 然而，由于复杂的交易流程和先进的资金隐藏技术，对无许可区块链的执行仍然具有挑战性。 以加密货币混币工具Tornado Cash为例，我们定量评估了美国外国资产控制办公室（OFAC）制裁在957天内的效果，涵盖了679万 Ethereum 区块和10.7亿笔交易。 我们的分析显示，尽管OFAC制裁使Tornado Cash的存款总量减少了71.03%，降至约20亿美元，但攻击者仍在78.33%的与Ethereum相关的安全事件中依赖Tornado Cash，这凸显了持续的规避策略。 我们发现当前制裁执行实践中存在三个结构性限制：(i) 二进制制裁分类易受灰尘攻击；(ii) 区块链生产者造成的碎片化审查；以及(iii) 用户利用的隐藏服务的复杂性。 为解决这些差距，我们引入了一种更实用的评分和跟踪算法，基于定量杂质。 平均而言，我们的算法在0.07$\pm$ 0.03秒内处理Ethereum区块，并在Bybit漏洞上评估时达到97.61%的精确率和74.08%的召回率。 我们的研究通过提供实证证据，澄清了执行挑战，并为应对制裁和基于区块链的安全风险提供了未来的合规策略，从而有助于去中心化金融领域的监管有效性讨论。 显示英文摘要

摘要： Sanctioning blockchain addresses has become a common regulatory response to malicious activities. However, enforcement on permissionless blockchains remains challenging due to complex transaction flows and sophisticated fund-obfuscation techniques. Using cryptocurrency mixing tool Tornado Cash as a case study, we quantitatively assess the effectiveness of U.S. Office of Foreign Assets Control (OFAC) sanctions over a 957-day period, covering 6.79 million Ethereum blocks and 1.07 billion transactions. Our analysis reveals that while OFAC sanctions reduced overall Tornado Cash deposit volume by 71.03% to approximately 2 billion USD, attackers still relied on Tornado Cash in 78.33% of Ethereum-related security incidents, underscoring persistent evasion strategies. We identify three structural limitations in current sanction enforcement practices: (i) the susceptibility of binary sanction classifications to dusting attacks; (ii) fragmented censorship by blockchain producers; and (iii) the complexity of obfuscation services exploited by users. To address these gaps, we introduce a more practical algorithm for scoring and tracking, grounded in quantitative impurity. On average, our algorithm processes Ethereum blocks within 0.07 $\pm$ 0.03 seconds and achieves 97.61% precision and 74.08% recall when evaluated on the Bybit exploit. Our findings contribute to ongoing discussions around regulatory effectiveness in Decentralized Finance by providing empirical evidence, clarifying enforcement challenges, and informing future compliance strategies in response to sanctions and blockchain-based security risks.