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Unformatted text preview: Using Directional Antennas to Prevent Wormhole Attacks Lingxuan Hu David Evans Department of Computer Science University of Virginia Charlottesville, VA [lingxuan, evans]@cs.virginia.edu Abstract Wormhole attacks enable an attacker with limited resources and no cryptographic material to wreak havoc on wireless networks. To date, no general defenses against wormhole attacks have been proposed. This paper presents an analysis of wormhole attacks and proposes a countermeasure using directional antennas. We present a cooperative protocol whereby nodes share directional information to prevent wormhole endpoints from masquerading as false neighbors. Our defense greatly diminishes the threat of wormhole attacks and requires no location information or clock synchronization. 1. Introduction Wireless ad hoc networks have properties that increase their vulnerability to attacks. Wireless links are inherently vulnerable to eavesdropping and message injection, as well as jamming attacks. Constraints in memory, computing power, and battery power in mobile devices can impose trade-offs between security and resource consumption. Routing in ad hoc wireless networks is an especially hard task to accomplish securely, robustly and efficiently. Many proposed routing protocols are focused on energy, and provide no protection against an adversary. Some secure routing protocols also have been proposed. However, due to the unpredictability of ad hoc networks, it is hard to detect behavior anomalies in route discovery. In particular, proposed routing protocols cannot prevent wormhole attacks. In a wormhole attack, an attacker introduces two transceivers into a wireless network and connects them with a high quality, low-latency link. Routing messages received by one wormhole endpoint are retransmitted at the other endpoint. Attackers can exploit wormholes to build bogus route information, selectively drop packets, and create routing loops to waste the energy of network. Wireless ad hoc networks typically assume omni- directional antennas. In this paper, we consider devices with directional antennas. Directional antennas have been shown to improve efficiency and capacity of wireless networks. Several MAC protocols [4, 14, 12, 20] and routing protocols [5, 2, 17] have been proposed that take advantage of directional antennas. Next we provide background on secure routing protocols and previous work on preventing wormhole attacks. Section 3 considers wormhole attacks and analyzes their effectiveness. Section 4 introduces directional antennas and describes the antenna model we use. Section 5 describes our protocols for verifying neighbor relationships. Section 6 considers the impact of our protocol on network connectivity and routing performance, and Section 7 analyzes the impact of directional errors. Section 8 concludes....
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- Spring '12
- Computer Science