Here is some of my current and planned research.

Privacy-preserving communications networks

Privacy-preserving communications networks allow people to communicate with each other, and to access online information, without automatically revealing personal information such as their Internet addresses. The largest such network (Tor) sees millions of users daily. However, Tor is pushing the limits of its scalability, and is also vulnerable to powerful global network observers.

Our group works on many aspects of these networks, with the goal of creating new systems with improved security, privacy, efficiency, and scalability properties. We have a considerable amount of experience in this topic, and a number of our improvements have been incorporated into the standard Tor software.

Privacy-preserving computation

Traditional encryption techniques are well suited for providing protection of information in transit or at rest. Normally, however, when the information is being actively processed, it is in decrypted form, and is at that point vulnerable to being leaked in a data breach.

Our group works on creating systems to achieve private computation, so that even the servers performing the computation do not have access to the sensitive data they are processing. We have works spanning a number of techniques to achieve privacy-preserving computation, including multiparty computation, trusted execution environments, oblivious algorithms, and homomorphic encryption.

Censorship resistance

Free and open communications on the Internet are a boon to the exchange of ideas, information, culture, and democracy around the world. Unfortunately, a number of national governments aim to restrict the ability of their citizens to freely communicate. Censorship resistance technologies use information hiding techniques to allow communication between a person inside a censored regime and the outside.

Our work on censorship resistance aims to design, develop, and deploy censorship resistance technologies that allow people worldwide to access the free and open Internet.

Applied cryptography

Much of the above research relies on techniques in applied cryptography, including secure multi-party computation, homomorphic encryption, private information retrieval, differential privacy, and zero-knowledge proofs. Our group both uses these techniques, and also innovates in them, producing more efficient algorithms, easy-to-use libraries, and ready-to-run systems.