Collaborative Research: AF: Medium: Foundations of Anonymous Communication in Large-Scale Networks

网络通信中的一个主要挑战是在不显著增加延迟和消息复杂性的情况下提供匿名性和隐私性。虽然人们知道如何通过适当的加密技术来保护信息的内容，但如何确保谁与谁通信仍然是私密的还不太清楚。目前使用的匿名技术，如Tor网络（每天有数百万人使用）是实用的，但不能提供可证明的匿名保证；事实上，安全研究人员已经证明，Tor很容易受到一种称为流量分析的互联网攻击。如何保证匿名性而不使当前系统过于不切实际，仍然是许多广泛使用的应用程序高度相关的开放问题。该项目创建和传播算法，实现严格和有效的匿名通信解决方案。该项目还包括研究生和本科生的教育计划，以在隐私、安全和计算机科学等关键领域建立更大的劳动力队伍。该项目解决了在网络通信中保证匿名性的基本挑战。隐藏元信息的技术（关于谁与谁、何时以及多长时间进行通信）不可避免地会增加通信（例如，通过中间节点重新路由通信和/或添加诱饵消息）。这反过来又可能导致网络拥塞和通信延迟。因此，一个具有理论和实践重要性的关键问题是理解在各种隐私措施和对抗模型下网络通信中安全性和消息复杂性之间的权衡。第二个挑战是在实际通信场景中设计可证明的安全高效的匿名通信方案，例如节点更换和迭代双向通信。研究团队将从两个方面解决这些挑战：(1)设计路由方案，使流量模式（可能被恶意节点改变）不会泄露任何元数据；(2)设计加密安全工具（如加密洋葱）来保护数据，即使负责中继的网络参与者可能是敌对的。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

A major challenge in network communication is providing anonymity and privacy without significant increase in latency and message complexity. While it is known how to secure the contents of messages via proper encryption techniques, it is less clear how to ensure that who is communicating with whom remains private, too. Currently used anonymity technologies such as the Tor network (used by millions daily) are practical but do not provide provable anonymity guarantees; in fact, security researchers have demonstrated that Tor is vulnerable to a type of Internet attack called traffic analysis. How to guarantee anonymity without rendering current systems too impractical remains an open question of high relevance to many widely used applications. This project create and disseminates algorithms that implement rigorous and efficient solutions to anonymous communication. The project also includes educational initiatives at the graduate and undergraduate levels to build a bigger workforce in the crucial area of privacy, security and computer science more generally.This project addresses the fundamental challenge of guaranteeing anonymity in network communications. Techniques for obscuring meta-information about who is communicating with whom, when, and for how long inevitably involve increased communication (e.g., by rerouting communication through intermediate nodes and/or adding decoy messages). This in turn may lead to network congestion and communication delays. Thus, a crucial question of both theoretical and practical importance is to understand the trade-offs between security and message complexity in network communications under various privacy measures and adversarial models. A second challenge is to design provably secure and efficient anonymous communication schemes in realistic communications scenarios, such as node churn and iterative two-way communications. The team of researchers will address these challenges along two facets: (1) Designing routing schemes so that traffic patterns, possibly altered by malicious nodes, do not reveal any metadata; and (2) Designing cryptographically secure tools (such as cryptographic onions) to secure data even when the network participants responsible for relaying it are potentially adversarial.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.