Agile Protocols: an Application of Active Networking to
Censor-Resistant Publishing Networks
Flux Research Group
School of Computing, University of Utah
50 S. Central Campus Drive Rm. 3190
Salt Lake City, Utah 84112 USA
In this thesis we argue that content distribution in the face of censorship is a
appropriate and feasible application of active networking. In the face of a
determined and powerful adversary, every fixed protocol can become known and
subsequently monitored, blocked, or its member nodes identified and attacked.
Rapid and diverse protocol change is key to allowing information to continue to
flow. Typically, decentralized protocol evolution is also an important aspect
in providing censor-resistance for publishing networks. These goals can be achie
ved with the help of
active networking techniques, by allowing new protocol implementations, in the
form of mobile code, to spread throughout the network.
A programmable overlay network can provide protocol change and decentralized
protocol evolution. Such a system, however, will need to take steps to ensure
that programmability does not present excessive security threats to the
network. Runtime isolation, protocol confidence ratings, encryption, and
resource control are vital in this respect.
We have prototyped such a system as an extension to Freenet, a storage and
retrieval system whose goals include censor resistance and anonymity for
information publishers and consumers. Our prototype implements many of the
mechanisms discussed in this thesis, indicating that our proposed
ideas are feasible to implement.