Photo credits: Jules Drean
Sacha Servan-Schreiber
3s [at]
Welcome to my digital corner!

I'm a Ph.D. student at MIT CSAIL, advised by Srini Devadas. Before MIT, I was an undergrad at Brown University.
My research is focused on applied cryptography. In my spare time I like to make art, cycle, and run around the Charles River.

GitHub · CV

Recent projects
Making Tor faster with Multi-hop Overlay Routing
Tor can be significantly slower compared to regular browsing largely due to the way in which Tor routes traffic over the internet. Tor requires routing packets through multiple relays forming a "circuit." Traffic congestions between relays on a Tor circuit can lead to delays, increasing latency, and hindering user experience. ShorTor is an overlay for the Tor network which can help find shorter paths between relays using a trick deployed by major CDNs. ShorTor reduces latency between relays, is incrementally deployable, and minimally impacts the security of Tor.

Paper · Slides · Code
Private Approximate Nearest Neighbor Search
How do you find and retrieve similar items (a.k.a. nearest neighbors) from a remote database without revealing what you're looking for? This project focuses on efficient privacy-preserving similarity search between a client and a remote database (replicated on two non-colluding servers), taking into consideration the privacy of the client and the database. Clients can efficiently query for nearest neighbors in the database without the high communication overhead of prior work.

Paper · Slides · Code

Talk given at: Berkeley University, IEEE S&P.
Private Targeted Advertising
Can we have privacy-preserving surveillance capitalism? In this paper, we explore how ad-tech companies can support high-fidelity targeted adverting while preserving user privacy. We design AdVeil: an ecosystem for private targeted advertising providing user data unlinkability and fraud-prevention guarantees.

Paper · Slides · Code

Talk given at: Cornell University, Brave Research, and Northeastern University.
High-bandwidth Anonymous Broadcasting
How do you broadcast high-bandwidth documents (e.g., video leaks) anonymously, even when the entire network is monitored?
We design Spectrum: a system for anonymously broadcasting large files over an untrusted network without leaking any metadata; even in the presence of a powerful network adversary.

Paper · Slides · Code

Talk given at: Cornell University, Northeastern University, NSDI.
Selected publications
© 2022 Sacha Servan-Schreiber