An anonymous overlay network allows internet users to connect to arbitrary
servers while concealing who communicates with whom. Several such schemes
have been deployed, including the popular Tor network that supports over
200,000 users. In this talk I will discuss how the approach to node
discovery in these deployed schemes inherently limits their scalability. I
will also outline attacks that severely reduce the anonymity of several
more scalable anonymous overlay networking schemes. Finally, I will
present Torsk, a design and implementation of an anonymous overlay network
that is as secure as Tor but has exponentially decreased node discovery
costs. These results are from joint work with Jon McLachlan, Andrew Tran,
and Yongdae Kim.
Nicholas Hopper is a McKnight Land Grant Professor in the department of
Computer Science and Engineering, University of Minnesota. He received a
B.A. from the University of Minnesota in 1999 and a Ph.D. in Computer
Science from Carnegie Mellon University in 2004. His research interests
include cryptography, computer security, and online privacy.