Packet leashes: a defense against wormhole attacks in wireless networks

TLDR

Mobile ad hoc networks increasingly rely on security, yet wormhole attacks—possible even without host compromise or broken authentication—pose a serious threat to routing protocols and location-based systems. The paper introduces the wormhole attack and proposes packet leashes, a general defense mechanism, with the TIK protocol as a concrete implementation. Packet leashes detect wormholes by verifying that packets cannot be transmitted over long distances, and the TIK protocol implements this detection mechanism. Without defenses, most ad hoc routing protocols cannot discover routes beyond one or two hops, severely disrupting communication.

Abstract

As mobile ad hoc network applications are deployed, security emerges as a central requirement. In this paper, we introduce the wormhole attack, a severe attack in ad hoc networks that is particularly challenging to defend against. The wormhole attack is possible even if the attacker has not compromised any hosts, and even if all communication provides authenticity and confidentiality. In the wormhole attack, an attacker records packets (or bits) at one location in the network, tunnels them (possibly selectively) to another location, and retransmits them there into the network. The wormhole attack can form a serious threat in wireless networks, especially against many ad hoc network routing protocols and location-based wireless security systems. For example, most existing ad hoc network routing protocols, without some mechanism to defend against the wormhole attack, would be unable to find routes longer than one or two hops, severely disrupting communication. We present a new, general mechanism, called packet leashes, for detecting and thus defending against wormhole attacks, and we present a specific protocol, called TIK, that implements leashes.