Privacy-enhanced social-network routing

Opportunistic networking—forwarding messages in a disconnected mobile ad hoc network via any encountered nodes — offers a new mechanism for exploiting the mobile devices that many users now carry. Forwarding messages in such a network often involves the use of social-network routing— sending messages via nodes in the sender or recipient’s friends list. Simple social-network routing, however, may broadcast these friends lists, which introduces privacy concerns.
This paper presents a threat analysis of the privacy risks in social-network routing. We introduce two complementary methods for enhancing privacy in social-network routing by obfuscating the friends lists used to inform routing decisions. We evaluate these methods using three real-world datasets, and find that it is possible to obfuscate the friends lists without leading to a significant decrease in routing performance, as measured by delivery cost, delay and ratio. We quantify the increase in security provided by this obfuscation, with reference to classes of attack which are mitigated.