Another sneak preview: “The Economics of Covert Community Detection and Hiding”
17 October 2008
Shishir Nagaraja has posted on his research web-site his latest work on “The Economics of Covert Community Detection and Hiding“. This extends the line of research myself and Bettina Wittneben started with our paper “The Economics of Mass Surveillance and the Questionable Value of Anonymous Communications“, where we showed that anonymous communications themselves are not preventing target selection. Shishir’s work shows that simple covertness strategies can instead make the job of the surveillance analyst much harder.
The full abstract reads:
“We present a model of surveillance based on the detection of community structure in social networks. We examine the extent of network topology information an adver sary is required to gather in order to obtain high quality intelligence about community membership. We show that selective surveillance strategies can improve the adversary’s resource efficiency. However, the use of counter-surveillance defence strategies can signifficantly reduce the adversary’s capability. We analyze two adversary models drawn from contemporary computer security literature, and explore the dynamics of community detection and hiding in these settings. Our results show that in the absence of counter-surveillance moves, placing a mere 8% of the network under surveillance can uncover the community membership of as much as 50% of the network. Uncovering all community information with targeted selection requires half the surveillance budget where parties use anonymous channels to communicate. Finally, the most determined covert community can escape detection by adopting decentralized counter-surveillance techniques even while facing an adversary with full topology knowledge – by investing in a small counter-surveillance budget, a rebel group can induce a steep increase in the false negative ratio.”