Active protocols for agile censor-resistant networks

The authors argue that content distribution in the face of censorship is a compelling 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. Frequent and diverse protocol change is key to allowing information to continue to flow. Typically, decentralized and locally-customized protocol evolution is also an important aspect in providing censor-resistance. A programmable overlay network can provide this type of manually-initiated protocol diversification. We have prototyped such an extension to Freenet, a peer-to-peer storage and retrieval system, whose goals include censor resistance and anonymity for information publishers and consumers.