TWC: Small: Efficient Traffic Analysis Resistance for Anonymity Networks

关心自己隐私的互联网用户，包括举报人和极权国家持不同政见的公民，依靠可靠的手段匿名访问互联网服务。然而，大众媒体最近公布的事件表明，这些服务在实践中几乎没有隐私和匿名性。例如，最近要求Twitter提供疑似维基解密支持者的联系细节的传票表明，政府可以很容易地发现网络用户的网络身份。为了恢复和促进互联网上的言论自由，有必要建立一个通信系统，以保护用户免受互联网活动的身份识别，即使是来自强大的对手，如国家行为者。拟议中的研究将通过设计、实施和部署匿名通信网络来实现这一点，这些网络可以防止窃听者识别互联网通信的来源、接收者或内容。像Tor这样的网络匿名服务提供了比直接与Twitter等网站通信更高程度的保护，但其设计无法承受流量分析（英国情报机构GCHQ正在积极寻求一种技术来对Tor用户进行去匿名化）。虽然一些研究人员提出了低延迟、抗流量分析的匿名网络设计，但这些系统的性能令人沮丧。这个项目将研究匿名网络设计，是弹性的流量分析，并表现出一个可接受的效益成本比下一些现实的假设。 该项目将利用三个关键思想：（i）将联合收割机可信基础设施（用于混合流量）与不可信P2P节点（用于可扩展性）相结合;（ii）纳入区域的概念，使用户能够选择他们信任其代理运行的管辖区;（iii）利用经验观察到的通信工作负载特性来开发优化设计，提供可接受的性能/成本权衡。 其目标是建立一个网络，为文件共享、Web流量和实时通信（VoIP）提供强对抗模型下的匿名保证，并适用于固定线路和移动的环境。

Internet users concerned about their privacy, including whistleblowers and dissident citizens of totalitarian states, depend on reliable means to access Internet services anonymously. However, recent events publicized in popular press demonstrate that these services offer little privacy and anonymity in practice. For example, recent subpoena requiring Twitter to provide connection details of suspected Wikileaks supporters showed that governments can readily discover the network identities of Web users. To restore and promote free speech on the Internet, there is a need for systems of communication that protect users from identification through their Internet activity---even from powerful adversaries such as state actors. The proposed research will enable this through design, implementation, and deployment of anonymous communication networks that prevent eavesdroppers from identifying the source, recipient, or content of Internet communication.Network anonymization services like Tor provide a higher degree of protection than direct communication with Web sites like Twitter, but are not designed to withstand traffic analysis (a technique that the British intelligence agency GCHQ is actively pursuing to deanonymize Tor users). While several researchers proposed designs for low-latency, traffic-analysis resistant anonymity networks, the performance of these systems was discouraging. This project will investigate anonymity network designs that are resilient to traffic analysis and that exhibit an acceptable benefit-cost ratio under some set of realistic assumptions. The project will leverage three key ideas: (i) combine trusted infrastructure (for mixing traffic) with untrusted P2P nodes (for scalability); (ii) incorporate the notion of zones to give users the ability to select the jurisdiction in which they trust their proxies to run; (iii) leverage empirically observed properties of communication workloads to develop optimized designs that provide acceptable performance/cost trade-offs. The goal is to produce networks that provide anonymity guarantees under a strong adversarial model for file sharing, Web traffic and real-time communication (VoIP), and that work for both fixed-line and mobile environments.