Jamming attacks and countermeasures in wireless personal area networks

xviii, 117 p. : ill. ; 30 cm.PolyU Library Call No.: [THS] LG51 .H577P COMP 2011 LiuGThe jamming attack is one of the serious threats to wireless sensor networks (WSNs)using the IEEE 802.15.4 standard. In such an attack, jammers, who launch the attack, can dramatically degrade the network performance by interfering transmitting packets. Therefore, the study of the jamming attack and its countermeasures has become an important aspect of the WSN security. First, we present an energy-efficient Reduction-of-Quality (EERoQ) attack against coordinators to prevent them from receiving normal packets from neighbors. Existing jamming attacks are not efficient because they rely on overwhelming the victim with load that constantly exceeds targets capacity. In EERoQ, attackers use periodic jamming signal to block the transmission of data packets or ACK frames. As a result, a sender node will enter the retransmission state continuously and the network throughput will dramatically decrease. We use potency to denote the efficiency of the attack and define potency to be the ratio of the damage caused by attackers to the cost of launching EERoQ. In our model, an attacker can maximize damage per unit cost by maximizing the attack potency. In EERoQ, the generation of jamming signal is one of the critical technologies to launch the attack. Therefore, we present a strategy for implementing jamming signal by exploiting the CSMA-CA mechanism. Our experiments on an IEEE 802.15.4 compatible sensor network show that the proposed attack strategy is an energy-efficient way to implement the RoQ attack.Second, we present an effective dynamic jamming attack (EDJam) in an 802.15.4-compliant WPAN and use the Stackelberg game to formulate the dynamic procedure of competition between the EDJam attacker and defending networks. Most existing jamming attacks can cause negative interference, but the attack strategies are usually not adjusted against the countermeasures that are currently taken. In the proposed attack, a jammer who is aware of a change in the network defense strategy, e.g. the use of a dynamic retransmission mechanism, may choose a better strategy to make more damage to the network with less cost. Similarly, a well-protected network can change its defense strategy against the EDJam. Therefore, a Stackelberg game can precisely reflect the procedure of a dynamic jamming attack and network defense. Moreover, we derive a unique Nash Equilibrium point in analytical format in this game. Based on an equilibrium analysis, we discuss the condition under which a defense strategy will increase the utility of the network and a dynamic retransmission mechanism defense strategy is proposed accordingly. The simulation results show that EDJam can be more cost-efficient than continuous, random and fixed-period jamming. Finally, we describe an energy-efficient keyless DSSS (EUDSSS) proposed for energy-constrained wireless networks. Prior research proposed various keyless spread spectrum technologies that focus on the capacity of jamming-resistant without the preshare secret key. Their design is not energy-efficient, which make them not suitable to be applied in energy-constrained networks such as wireless sensor networks. Therefore, we proposed the EUDSSS to balance the capacity of jamming-resistance and overhead by maximizing the tradeoff between correct bit rate and the additional communication bits comparing with traditional DSSS. The simulation results show that EUDSSS can achieve adequate reliability with small overhead.Department of ComputingPh.D., Dept. of Computing, The Hong Kong Polytechnic University, 201