Dynamic routing in covert channel overlays based on control protocols

Covert channels aim to carry information in a way prohibited by the security policy and can be used to bypass censorship (e.g. by journalists). To establish secure covert channel communications, overlay networks with internal control protocols can be built. We present a design method for control protocols within covert channels. Our protocol design provides the advantage of space-efficiency (in comparison to existing control protocols) and the advantage of dynamic extensibility. We apply the protocol design to realize OLSR-based dynamic routing for covert channel overlays. Our algorithm provides different optimization means to maximize the covertness and the connection quality of the channel. The approach is validated by an extensible prototype.