TWC: TTP Option: Small: Collaborative: Enhancing Anonymity Network Resilience against Pervasive Internet Attacks

大规模的互联网审查阻止了世界许多地区的公民获取大量原本可以公开获得的信息。对这些审查事件的承认和公布有助于推动新的增强隐私的技术的发展，以绕过审查。我们认为，随着规避技术的改进和检测其使用的成本增加，意图限制信息访问的对手将寻找替代技术来破坏。因此，了解这些替代中断技术及其如何影响网络匿名性、隐私和性能不仅对未来技术的成功设计至关重要，而且对现有网络和系统的安全也至关重要。因此，该项目探索、设计并过渡到实践技术，以提高隐私增强技术应对这些现实但未被充分研究的网络匿名性、隐私和可用性威胁的弹性。我们认为敌人超越了软件实现或协议中的弱点，而是试图通过影响匿名服务所依赖的共享资源来破坏这些服务的稳定。本项目研究互联网基础设施攻击如何应用于匿名网络。该研究设计了可提高对此类威胁的恢复能力的防御措施，并将此类防御措施过渡到部署的ToR网络。我们的研究活动(I)研究基于性能的资源攻击并设计隐私保护检测技术，以了解拒绝服务攻击如何耗尽网络资源，更重要的是，如何自动检测和阻止此类攻击；(Ii)研究控制平面路由攻击如何被用来损害匿名性，并开发攻击缓解技术以了解如何提高匿名网络对来自底层不可信互联网基础设施的威胁的弹性；以及(Iii)分析人类移动性对匿名的影响，以了解如何为现在无处不在的移动操作环境提供健壮和安全的匿名服务。这些活动有助于扩大未得到充分研究的研究领域，不仅有助于改进未来技术的设计，而且还增强了现有网络和系统的安全性。

Large-scale Internet censorship prevents citizens of many parts of the world from accessing vast amounts of otherwise publicly available information. The recognition and publication of these censorship events have aided in motivating the development of new privacy-enhancing technologies to circumvent the censor. We argue that as circumvention technologies improve and the cost of detecting their use increases, adversaries that are intent on restricting access to information will seek out alternative techniques for disruption. As such, understanding these alternative disruption techniques and how they affect network anonymity, privacy, and performance is paramount not only to the successful design of future technologies, but also to the security of existing networks and systems. Accordingly, this project explores, designs, and transitions to practice techniques that will improve the resilience of privacy-enhancing technologies against these realistic but understudied threats to network anonymity, privacy, and availability. We consider adversaries that look beyond weaknesses in software implementations or protocols and instead seek to destabilize anonymity services by affecting the shared resources upon which these services depend. This project studies how Internet infrastructure attacks apply to anonymity networks. The research designs defenses that improve the resilience against such threats, and transitions such defenses to the deployed Tor network. Our research activities (i) examine performance-based resource attacks and design privacy-preserving detection techniques to understand not only how denial-of-service attacks can drain network resources, but more importantly, how to automatically detect and prevent such attacks; (ii) study how control-plane routing attacks can be used to harm anonymity, and develop attack mitigation techniques to understand how to improve the resilience of anonymity networks against threats from the underlying untrusted Internet infrastructure; and (iii) analyze the impact of human mobility on anonymity to understand how to provide robust and secure anonymity services to the now ubiquitous mobile operating environment. The activities help expand understudied research areas and not only help improve the design of future technologies, but also enhance the security of existing networks and systems.