Contact Avoidance Routing in Delay Tolerant Networks

Delay tolerant networks (DTNs) are widely adopted to many network applications, such as disaster recovery and battlefield communications. Such critical network scenarios call for an outright prevention mechanism against contact-based attacks, e.g., blackmailing a legitimate user to compromise sensitive information at a contact. To the best of our knowledge, there is no work on secure routing protocol against contact-based attacks in DTNs. Therefore, in this paper, we first formulate the problem of contact avoidance routing, in which the node holding a message tries to avoid having a contact with an adversary. By applying the phase-type distribution, we build the secure opportunistic path model, which integrates the delivery probability within the deadline and the safety of opportunistic paths. Then, we propose a contact avoidance routing (CAR) protocol to securely deliver a message to its destination against the contact-based compromise attack. In addition, we further propose an adaptive CAR (A-CAR) to accommodate complicated network scenarios, where the capabilities of adversaries are parameterized. The extensive simulations using real traces as well as random graphs demonstrate that the proposed CAR and A-CAR protocols achieve their design goals.