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 ∗Corresponding author. Email addresses: [email protected] (Iain Parris), [email protected] (Tristan Henderson) URL: http://www.cs.st-andrews.ac.uk/ ̃ip/ (Iain Parris), http://www.cs.st-andrews.ac.uk/ ̃tristan/ (Tristan Henderson) 1Phone: +44 1334 463253 Fax: +44 1334 463278 Preprint submitted to Computer Communications June 6, 2010 the increase in security provided by this obfuscation, with reference to classes of attack which are mitigated.