Browsing by Subject "security"
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Item Architectural support for enhancing security in clusters(2009-05-15) Lee, Man HeeCluster computing has emerged as a common approach for providing more comput- ing and data resources in industry as well as in academia. However, since cluster computer developers have paid more attention to performance and cost e?ciency than to security, numerous security loopholes in cluster servers come to the forefront. Clusters usually rely on ?rewalls for their security, but the ?rewalls cannot prevent all security attacks; therefore, cluster systems should be designed to be robust to security attacks intrinsically. In this research, we propose architectural supports for enhancing security of clus- ter systems with marginal performance overhead. This research proceeds in a bottom- up fashion starting from enforcing each cluster component's security to building an integrated secure cluster. First, we propose secure cluster interconnects providing con- ?dentiality, authentication, and availability. Second, a security accelerating network interface card architecture is proposed to enable low performance overhead encryption and authentication. Third, to enhance security in an individual cluster node, we pro- pose a secure design for shared-memory multiprocessors (SMP) architecture, which is deployed in many clusters. The secure SMP architecture will provide con?dential communication between processors. This will remove the vulnerability of eavesdrop- ping attacks in a cluster node. Finally, to put all proposed schemes together, we propose a security/performance trade-o? model which can precisely predict performance of an integrated secure cluster.Item Collusion-resistant fingerprinting for multimedia in a broadcast channel environment(Texas A&M University, 2005-02-17) Luh, WilliamDigital fingerprinting is a method by which a copyright owner can uniquely embed a buyer-dependent, inconspicuous serial number (representing the fingerprint) into every copy of digital data that is legally sold. The buyer of a legal copy is then deterred from distributing further copies, because the unique fingerprint can be used to trace back the origin of the piracy. The major challenge in fingerprinting is collusion, an attack in which a coalition of pirates compare several of their uniquely fingerprinted copies for the purpose of detecting and removing the fingerprints. The objectives of this work are two-fold. First, we investigate the need for robustness against large coalitions of pirates by introducing the concept of a malicious distributor that has been overlooked in prior work. A novel fingerprinting code that has superior codeword length in comparison to existing work under this novel malicious distributor scenario is developed. In addition, ideas presented in the proposed fingerprinting design can easily be applied to existing fingerprinting schemes, making them more robust to collusion attacks. Second, a new framework termed Joint Source Fingerprinting that integrates the processes of watermarking and codebook design is introduced. The need for this new paradigm is motivated by the fact that existing fingerprinting methods result in a perceptually undistorted multimedia after collusion is applied. In contrast, the new paradigm equates the process of collusion amongst a coalition of pirates, to degrading the perceptual characteristics, and hence commercial value of the multimedia in question. Thus by enforcing that the process of collusion diminishes the commercial value of the content, the pirates are deterred from attacking the fingerprints. A fingerprinting algorithm for video as well as an efficient means of broadcasting or distributing fingerprinted video is also presented. Simulation results are provided to verify our theoretical and empirical observations.Item Covert Communication Networks(2013-08-02) Nix, Timothy GlenA covert communications network (CCN) is a connected, overlay peer-to-peer network used to support communications within a group in which the survival of the group depends on the confidentiality and anonymity of communications, on concealment of participation in the network to both other members of the group and external eavesdroppers, and finally on resilience against disconnection. In this dissertation, we describe the challenges and requirements for such a system. We consider the topologies of resilient covert communications networks that: (1) minimize the impact on the network in the event of a subverted node; and (2) maximize the connectivity of the survivor network with the removal of the subverted node and its closed neighborhood. We analyze the properties of resilient covert networks, propose measurements for determining the suitability of a topology for use in a covert communication network, and determine the properties of an optimal covert network topology. We analyze multiple topologies and identify two constructions that are capable of generating optimal topologies. We then extend these constructions to produce near-optimal topologies that can ?grow? as new nodes join the network. We also address protocols for membership management and routing. Finally, we describe the architecture of a prototype system for instantiating a CCN.Item Female Perpetrated Terrorism and Suicide BombingsWillows, Amanda Ann; Celso, Anthony N; Taylor, William A; Bechtol, Bruce E; Serrano, GabriellaHistorically, women have played important roles in terrorist organizations. The roles of women in terrorist organizations, however, have been more supportive than militant. The duties given to these women were to reproduce, providing more fighters and supporting and caring for the men as they fought and gathered intelligence. In recent decades, female roles in terrorist organizations have changed and they are being utilized in more instrumental ways. Females who have lost their husbands and loved ones to government forces appear to be ideal for recruitment. Their male counterparts have discovered their usefulness on the front lines as the ultimate smart bombs. In this study, we seek to gain a better understanding of female perpetrated terrorism and the etiology of female suicide bombers.Item Interdependent infrastructures and multi-mode attacks and failures: improving the security of urban water systems and fire response(2009-05-15) Bristow, Elizabeth CatherineThis dissertation examines the interdependence between urban water distribution systems and urban fire response. The focus on interdependent critical infrastructures is driven by concern for security of water systems and the effects on related infrastructures if water distribution systems are damaged by terrorist attack or natural disaster. A model of interdependent infrastructures (principally water distribution systems and fire response) is developed called the Model of Urban Fire Spread (MUFS). The model includes the capacity to simulate firefighting water demands in a community water system hydraulic model, building-to-building urban fire spread, and suppression activities. MUFS is an improvement over previous similar models because it allows simulation of urban fires at the level of individual buildings and it permits simulation of interdependent infrastructures working in concert. MUFS is used to simulate a series of multi-mode attacks and failures (MMAFs) ? events which disable the water distribution system and simultaneously ignite an urban fire. The consequences of MMAF scenarios are analyzed to determine the most serious modes of infrastructure failure and urban fire ignition. Various methods to determine worst-case configurations of urban fire ignition points are also examined. These MMAF scenarios are used to inform the design of potential mitigation measures to decrease the consequences of the urban fire. The effectiveness of mitigation methods is determined using the MUFS simulation tool. Novel metrics are developed to quantify the effectiveness of the mitigation methods from the time-series development of their consequences. A cost-benefit analysis of the various mitigation measures is conducted to provide additional insight into the methods? effectiveness and better inform the decision-making process of selecting mitigation methods. Planned future work includes further refinement of the representation of fire propagation and suppression in MUFS and investigation of historical MMAF events to validate simulation predictions. Future efforts will continue development of appropriate optimization methods for determining worst-case MMAF scenarios. This work should be of interest to water utility managers and emergency planners, who can adapt the methodology to analyze their communities? vulnerability to MMAFs and design mitigation techniques to meet their unique needs, as well as to researchers interested in infrastructure modeling and disaster simulation.Item Quality of Service (QoS) security in mobile ad hoc networks(Texas A&M University, 2006-10-30) Lu, BinWith the rapid proliferation of wireless networks and mobile computing applications, Quality of Service (QoS) for mobile ad hoc networks (MANETs) has received increased attention. Security is a critical aspect of QoS provisioning in the MANET environment. Without protection from a security mechanism, attacks on QoS signaling system could result in QoS routing malfunction, interference of resource reservation, or even failure of QoS provision. Due to the characteristics of the MANETs, such as rapid topology change and limited communication and computation capacity, the conventional security measures cannot be applied and new security techniques are necessary. However, little research has been done on this topic. In this dissertation, the security issues will be addressed for MANET QoS systems. The major contributions of this research are: (a) design of an authentication mechanism for ad hoc networks; (b) design of a security mechanism to prevent and detect attacks on the QoS signaling system; (c) design of an intrusion detection mechanism for bandwidth reservation to detect QoS attacks and Denial of Service (DoS) attacks. These three mechanisms are evaluated through simulation.Item Secure Integrated Routing and Localization in Wireless Optical Sensor Networks(2009-05-15) Okorafor, Unoma NdiliWireless ad hoc and sensor networks are envisioned to be self-organizing and autonomous networks, that may be randomly deployed where no fixed infrastructure is either feasible or cost-effective. The successful commercialization of such networks depends on the feasible implementation of network services to support security-aware applications. Recently, free space optical (FSO) communication has emerged as a viable technology for broadband distributed wireless optical sensor network (WOSN) applications. The challenge of employing FSO include its susceptibility to adverse weather conditions and the line of sight requirement between two communicating nodes. In addition, it is necessary to consider security at the initial design phase of any network and routing protocol. This dissertation addresses the feasibility of randomly deployed WOSNs employing broad beam FSO with regard to the network layer, in which two important problems are specifically investigated. First, we address the parameter assignment problem which considers the relationship amongst the physical layer parameters of node density, transmission radius and beam divergence of the FSO signal in order to yield probabilistic guarantees on network connectivity. We analyze the node isolation property of WOSNs, and its relation to the connectivity of the network. Theoretical analysis and experimental investigation were conducted to assess the effects of hierarchical clustering as well as fading due to atmospheric turbulence on connectivity, thereby demonstrating the design choices necessary to make the random deployment of the WOSN feasible. Second, we propose a novel light-weight circuit-based, secure and integrated routing and localization paradigm within the WOSN, that leverages the resources of the base station. Our scheme exploits the hierarchical cluster-based organization of the network, and the directionality of links to deliver enhanced security performance including per hop and broadcast authentication, confidentiality, integrity and freshness of routing signals. We perform security and attack analysis and synthesis to characterize the protocol?s performance, compared to existing schemes, and demonstrate its superior performance for WOSNs. Through the investigation of this dissertation, we demonstrate the fundamental tradeoff between security and connectivity in WOSNs, and illustrate how the transmission radius may be used as a high sensitivity tuning parameter to balance there two metrics of network performance. We also present WOSNs as a field of study that opens up several directions for novel research, and encompasses problems such as connectivity analysis, secure routing and localization, intrusion detection, topology control, secure data aggregation and novel attack scenarios.