SaTC: CORE: Small: Design of Efficient, Horizontally-Scaling, and Strongly Anonymous Communication Networks

匿名通信是言论自由的一个重要方面。在许多情况下，匿名仍然是表达不受欢迎或被禁止的意见的人最重要的辩护，从反对镇压政府的抗议组织者到报告针对强大实体的敏感新闻的举报人。由于其重要性，在过去的几十年里，已经有许多系统被设计来保护用户的匿名性。不幸的是，大多数现有的匿名系统分为两类：防御全球对手但难以扩展且效率低下的系统，以及易于扩展且效率高但无法防御强大对手的系统。因此，匿名网络管理员被迫要么只支持有限数量的用户，要么遭受针对其系统的攻击。该项目旨在设计、实施和部署一个结合了这两个类别的最佳方面的系统，以产生一个高效的匿名通信网络，该网络可以轻松扩展，同时提供针对全球对手的可证明保证。这样的系统可以通过保证大量用户的强匿名性来增强用户的言论自由，并为当今的互联网用户提供更多的隐私增强选择。本项目的技术目标是创建一个系统，该系统提供可证明的匿名性，以对抗控制（1）所有参与者之间的网络连接（2）大量用户，以及（3）服务器的任何部分，同时通过更多服务器扩展到大量用户。为了达到这个目标，这个项目将回答以下三个问题：（1）系统如何组织和利用服务器在一个可伸缩的方式提供匿名对对手监视整个互联网？(2)系统如何防止恶意用户偏离协议？(3)系统如何防止恶意服务器对用户进行去匿名化？这些问题的答案将导致一个可扩展的强匿名系统的设计。这个设计的原型将在一个由许多服务器组成的志愿者网络中实现、评估和部署，以努力接触到广泛的用户。除了研究生论文外，该项目还将为参加MIT PRIMES外展计划的高中生以及通过MIT本科生研究机会计划为MIT本科生提供研究项目。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

Anonymous communication is an important aspect of freedom of speech. In many cases, anonymity remains the most important defense for persons expressing unpopular or prohibited opinions, from protest organizers who are fighting against repressive governments to whistleblowers who report sensitive news against powerful entities. Owing to its importance, there have been many systems that were designed to protect users' anonymity in the past several decades. Unfortunately, most existing anonymity systems fall into one of two categories: systems that defend against global adversaries but are hard to scale and inefficient, and systems that are easy to scale and efficient but do not defend against powerful adversaries. Thus, anonymity network administrators are forced to either support only a limited number of users or suffer from attacks against their system. This project aims to design, implement, and deploy a system that marries the best aspects of the two categories so as to produce an efficient anonymous communication network that can scale easily while providing provable guarantees against a global adversary. Such a system can enhance users' freedom of speech by guaranteeing strong anonymity for a large number of users, and provide more privacy enhancing choices for Internet users today.The technical goal of this project is to create a system that provides provable anonymity against an adversary that controls (1) the network connection between all participants (2) a large number of users, and (3) any fraction of the servers, while scaling to large numbers of users with more servers. To achieve this goal, this project will answer the following three questions: (1) How can the system organize and utilize the servers in a scalable manner to provide anonymity against an adversary that monitors all of Internet? (2) How does the system prevent malicious users from deviating from the protocol? (3) How does the system prevent malicious servers from de-anonymizing users? The answers to these questions will lead to the design of a scalable strong anonymity system. A prototype of this design will be implemented, evaluated, and deployed across a volunteer network of many servers in an effort to reach a broad audience of users. In addition to graduate student theses, this project will provide research projects for high school students who are part of the MIT PRIMES outreach program, as well as MIT undergraduates through the MIT Undergraduate Research Opportunities Program.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.