17 research outputs found

    Optimal Strategies in Jamming Resistant Uncoordinated Frequency Hopping Systems

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    Uncoordinated frequency hopping (UFH) has recently emerged as an effective mechanism to defend against jamming attacks. Existing research focuses on the optimal design of the hopping pattern, which implicitly assumes that the strategy of the attacker is fixed. In practice, the attacker might adjust its strategy to maximize its damage on the communication system. In this thesis, we study the design of optimal hopping pattern (the defense strategy) as long as the optimal jamming pattern (the attack strategy). In particular, we model the dynamic between the legitimate users and the attacker as a zero sum game, and study the property of this game. We show that when the legitimate users and the jammer can access only one channel at any time, the game has a unique Nash equilibrium. In the Nash equilibrium, the legitimate users and Eve will access or jam only a subset of channels that have good channel quality. Furthermore, the better the channel, the larger the probability that Eve will jam the channel and the smaller the probability the legitimate users will access this channel. We further extend the study to multiple access multiple jamming case and characterize the Nash equilibrium. We also give numerical results to illustrate the analytical results derived in this thesis

    Wideband Anti-Jamming Based on Free Space Optical Communication and Photonic Signal Processing

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    We propose and demonstrate an anti-jamming system to defend against wideband jamming attack. Free space optical communication is deployed to provide a reference for jamming cancellation. The mixed signal is processed and separated with photonic signal processing method to achieve large bandwidth. As an analog signal processing method, the cancellation system introduces zero latency. The radio frequency signals are modulated on optical carriers to achieve wideband and unanimous frequency response. With wideband and zero latency, the system meets the key requirements of high speed and real-time communications in transportation systems

    Synoptic analysis techniques for intrusion detection in wireless networks

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    Current system administrators are missing intrusion alerts hidden by large numbers of false positives. Rather than accumulation more data to identify true alerts, we propose an intrusion detection tool that e?ectively uses select data to provide a picture of ?network health?. Our hypothesis is that by utilizing the data available at both the node and cooperative network levels we can create a synoptic picture of the network providing indications of many intrusions or other network issues. Our major contribution is to provide a revolutionary way to analyze node and network data for patterns, dependence, and e?ects that indicate network issues. We collect node and network data, combine and manipulate it, and tease out information about the state of the network. We present a method based on utilizing the number of packets sent, number of packets received, node reliability, route reliability, and entropy to develop a synoptic picture of the network health in the presence of a sinkhole and a HELLO Flood attacker. This method conserves network throughput and node energy by requiring no additional control messages to be sent between the nodes unless an attacker is suspected. We intend to show that, although the concept of an intrusion detection system is not revolutionary, the method in which we analyze the data for clues about network intrusion and performance is highly innovative

    Compromise-resilient anti-jamming communication in wireless sensor networks

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    Estimating the Relative Speed of RF Jammers in VANETs

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    Vehicular Ad Hoc Networks (VANETs) aim at enhancing road safety and providing a comfortable driving environment by delivering early warning and infotainment messages to the drivers. Jamming attacks, however, pose a significant threat to their performance. In this paper, we propose a novel Relative Speed Estimation Algorithm (RSEA) of a moving vehicle that approaches a transmitter ()-receiver () pair that interferes with their radio frequency (RF) communication by conducting a denial of service (DoS) attack. Our scheme is completely passive and uses a pilot-based received signal without hardware or computational cost to, firstly, estimate the combined channel between the transmitter-receiver and jammer-receiver and, secondly, to estimate the jamming signal and the relative speed between the jammer-receiver using the RF Doppler shift. Moreover, the relative speed metric exploits the angle of projection (AOP) of the speed vector of the jammer in the axis of its motion in order to form a two-dimensional representation of the geographical area. Our approach can effectively be applied for any form of the jamming signal and is proven to have quite accurate performance, with a mean absolute error (MAE) value of approximately compared to the optimal zero MAE value under different jamming attack scenarios
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