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