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Theses and Dissertations

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Articles 61 - 90 of 180

Full-Text Articles in Digital Communications and Networking

Dynamic Network Topologies, Heather A. Lingg Jun 2013

Dynamic Network Topologies, Heather A. Lingg

Theses and Dissertations

Demand for effective network defense capabilities continues to increase as cyber attacks occur more and more frequently and gain more and more prominence in the media. Current security practices stop after data encryption and network address filtering. Security at the lowest level of network infrastructure allows for greater control of how the network traffic flows around the network. This research details two methods for extending security practices to the physical layer of a network by modifying the network infrastructure. The first method adapts the Advanced Encryption Standard while the second method uses a Steiner tree. After the network connections are …


Classification Of Encrypted Web Traffic Using Machine Learning Algorithms, William C. Barto Jun 2013

Classification Of Encrypted Web Traffic Using Machine Learning Algorithms, William C. Barto

Theses and Dissertations

The increasing usage of web services and encrypted network communication makes the network analysis of encrypted web traffic of utmost importance. This research evaluates the feasibility of using ML algorithms to classify web services within encrypted TLS flows. The ML algorithms are compared primarily based on classification accuracy. The runtimes of the classifiers are also considered, as classifiers must be able determine labels quickly in order to be used in near realtime network protection devices. Five ML algorithms are initially considered when analyzing only the first 12 packets: Naive Bayes, NBTree, LibSVM, J4.8, and AdaBoost+J4.8. AdaBoost+J4.8 and J4.8 produce the …


Applied Hypergame Theory For Network Defense, Alan S. Gibson Jun 2013

Applied Hypergame Theory For Network Defense, Alan S. Gibson

Theses and Dissertations

Cyber operations are the most important aspect of military conflicts in the 21st century, but unfortunately they are also among the least understood. The continual battle for network dominance between attackers and defenders is considered to be a complex game. Hypergame theory is an extension of game theory that addresses the kind of games where misperception exists, as is often the case in military engagements. Hypergame theory, like game theory, uses a game model to determine strategy selection, but goes beyond game theory by examining subgames that exist within the full game. The inclusion of misperception and misinformation in the …


Evaluating The Effectiveness Of Ip Hopping Via An Address Routing Gateway, Ryan A . Morehart Mar 2013

Evaluating The Effectiveness Of Ip Hopping Via An Address Routing Gateway, Ryan A . Morehart

Theses and Dissertations

This thesis explores the viability of using Internet Protocol (IP) address hopping in front of a network as a defensive measure. This research presents a custom gateway-based IP hopping solution called Address Routing Gateway (ARG) that acts as a transparent IP address hopping gateway. This thesis tests the overall stability of ARG, the accuracy of its classifications, the maximum throughput it can support, and the maximum rate at which it can change IPs and still communicate reliably. This research is accomplished on a physical test network with nodes representing the types of hosts found on a typical, corporate-style network. Direct …


Modeling Cyber Situational Awareness Through Data Fusion, Evan L. Raulerson Mar 2013

Modeling Cyber Situational Awareness Through Data Fusion, Evan L. Raulerson

Theses and Dissertations

Cyber attacks are compromising networks faster than administrators can respond. Network defenders are unable to become oriented with these attacks, determine the potential impacts, and assess the damages in a timely manner. Since the observations of network sensors are normally disjointed, analysis of the data is overwhelming and time is not spent efficiently. Automation in defending cyber networks requires a level of reasoning for adequate response. Current automated systems are mostly limited to scripted responses. Better defense tools are required. This research develops a framework that aggregates data from heterogeneous network sensors. The collected data is correlated into a single …


Rf Emitter Tracking And Intent Assessment, Benjamin J. Kuhar Mar 2013

Rf Emitter Tracking And Intent Assessment, Benjamin J. Kuhar

Theses and Dissertations

Current research in employing pattern recognition techniques in a wireless sensor network (WSN) to detect anomalous or suspicious behavior is limited. The purpose of this research was to determine the feasibility of an accurate tracking and intent assessment system of unknown or foreign radio frequency (RF) emitters in close proximity to and within military installations as a method for physical security. 22 position tracks were collected using a hand-held Global Positioning System (GPS) unit and a training data set from five different features was generated for each position track. Each collected position track was individually classified as suspicious or non-suspicious …


Rootkit Detection Using A Cross-View Clean Boot Method, Bridget N. Flatley Mar 2013

Rootkit Detection Using A Cross-View Clean Boot Method, Bridget N. Flatley

Theses and Dissertations

In cyberspace, attackers commonly infect computer systems with malware to gain capabilities such as remote access, keylogging, and stealth. Many malware samples include rootkit functionality to hide attacker activities on the target system. After detection, users can remove the rootkit and associated malware from the system with commercial tools. This research describes, implements, and evaluates a clean boot method using two partitions to detect rootkits on a system. One partition is potentially infected with a rootkit while the other is clean. The method obtains directory listings of the potentially infected operating system from each partition and compares the lists to …


Using Rf-Dna Fingerprints To Discriminate Zigbee Devices In An Operational Environment, Clay K. Dubendorfer Mar 2013

Using Rf-Dna Fingerprints To Discriminate Zigbee Devices In An Operational Environment, Clay K. Dubendorfer

Theses and Dissertations

This research was performed to expand AFIT's Radio Frequency Distinct Native Attribute (RF-DNA) fingerprinting process to support IEEE 802.15.4 ZigBee communication network applications. Current ZigBee bit-level security measures include use of network keys and MAC lists which can be subverted through interception and spoofing using open-source hacking tools. This work addresses device discrimination using Physical (PHY) waveform alternatives to augment existing bit-level security mechanisms. ZigBee network vulnerability to outsider threats was assessed using Receiver Operating Characteristic (ROC) curves to characterize both Authorized Device ID Verification performance (granting network access to authorized users presenting true bit-level credentials) and Rogue Device Rejection …


Cognitive Augmentation For Network Defense, James E. Emge Mar 2013

Cognitive Augmentation For Network Defense, James E. Emge

Theses and Dissertations

Traditionally, when a task is considered for automation it is a binary decision, either the task was completely automated or it remains manual. LOA is a departure from the tradition use of automation in cyber defense. When a task is automated, it removes the human administrator from the performance of the task, compromising their SA of the state of the network. When the administrator loses SA of the network performance and its current state, failure recovery time becomes much longer. This is because the administrators must orient themselves to the current state of the network at the time of failure …


Learning Enterprise Malware Triage From Automatic Dynamic Analysis, Jonathan S. Bristow Mar 2013

Learning Enterprise Malware Triage From Automatic Dynamic Analysis, Jonathan S. Bristow

Theses and Dissertations

Adversaries employ malware against victims of cyber espionage with the intent of gaining unauthorized access to information. To that end, malware authors intentionally attempt to evade defensive countermeasures based on static methods. This thesis analyzes a dynamic analysis methodology for malware triage that applies at the enterprise scale. This study captures behavior reports from 64,987 samples of malware randomly selected from a large collection and 25,591 clean executable files from operating system install media. Function call information in sequences of behavior generate feature vectors from behavior reports from the les. The results of 64 experiment combinations indicate that using more …


Mobile Network Defense Interface For Cyber Defense And Situational Awareness, James C. Hannan Mar 2013

Mobile Network Defense Interface For Cyber Defense And Situational Awareness, James C. Hannan

Theses and Dissertations

Today's computer networks are under constant attack. In order to deal with this constant threat, network administrators rely on intrusion detection and prevention services (IDS) (IPS). Most IDS and IPS implement static rule sets to automatically alert administrators and resolve intrusions. Network administrators face a difficult challenge, identifying attacks against a vast number of benign network transactions. Also after a threat is identified making even the smallest policy change to the security software potentially has far-reaching and unanticipated consequences. Finally, because the administrator is primarily responding to alerts they may lose situational awareness of the network. During this research a …


Emulation Of Industrial Control Field Device Protocols, Robert M. Jaromin Mar 2013

Emulation Of Industrial Control Field Device Protocols, Robert M. Jaromin

Theses and Dissertations

It has been shown that thousands of industrial control devices are exposed to the Internet, however, the extent and nature of attacks on such devices remains unknown. The first step to understanding security problems that face modern supervisory control and data acquisition (SCADA) and industrial controls networks is to understand the various attacks launched on Internet-connected field devices. This thesis describes the design and implementation of an industrial control emulator on a Gumstix single-board computer as a solution. This emulator acts as a decoy field device, or honeypot, intended to be probed and attacked via an Internet connection. Evaluation techniques …


Development Of A Response Planner Using The Uct Algorithm For Cyber Defense, Michael P. Knight Mar 2013

Development Of A Response Planner Using The Uct Algorithm For Cyber Defense, Michael P. Knight

Theses and Dissertations

A need for a quick response to cyber attacks is a prevalent problem for computer network operators today. There is a small window to respond to a cyber attack when it occurs to prevent significant damage to a computer network. Automated response planners offer one solution to resolve this issue. This work presents Network Defense Planner System (NDPS), a planner dependent on the effectiveness of the detection of the cyber attack. This research first explores making classification of network attacks faster for real-time detection, the basic function Intrusion Detection System (IDS) provides. After identifying the type of attack, learning the …


A Multi Agent System For Flow-Based Intrusion Detection, David A . Ryan Mar 2013

A Multi Agent System For Flow-Based Intrusion Detection, David A . Ryan

Theses and Dissertations

The detection and elimination of threats to cyber security is essential for system functionality, protection of valuable information, and preventing costly destruction of assets. This thesis presents a Mobile Multi-Agent Flow-Based IDS called MFIREv3 that provides network anomaly detection of intrusions and automated defense. This version of the MFIRE system includes the development and testing of a Multi-Objective Evolutionary Algorithm (MOEA) for feature selection that provides agents with the optimal set of features for classifying the state of the network. Feature selection provides separable data points for the selected attacks: Worm, Distributed Denial of Service, Man-in-the-Middle, Scan, and Trojan. This …


Airborne Network Data Availability Using Peer To Peer Database Replication On A Distributed Hash Table, Trevor J. Vranicar Mar 2013

Airborne Network Data Availability Using Peer To Peer Database Replication On A Distributed Hash Table, Trevor J. Vranicar

Theses and Dissertations

The concept of distributing one complex task to several smaller, simpler Unmanned Aerial Vehicles (UAVs) as opposed to one complex UAV is the way of the future for a vast number of surveillance and data collection tasks. One objective for this type of application is to be able to maintain an operational picture of the overall environment. Due to high bandwidth costs, centralizing all data may not be possible, necessitating a distributed storage system such as mobile Distributed Hash Table (DHT). A difficulty with this maintenance is that for an Airborne Network (AN), nodes are vehicles and travel at high …


Network Intrusion Dataset Assessment, David J. Weller-Fahy Mar 2013

Network Intrusion Dataset Assessment, David J. Weller-Fahy

Theses and Dissertations

Research into classification using Anomaly Detection (AD) within the field of Network Intrusion Detection (NID), or Network Intrusion Anomaly Detection (NIAD), is common, but operational use of the classifiers discovered by research is not. One reason for the lack of operational use is most published testing of AD methods uses artificial datasets: making it difficult to determine how well published results apply to other datasets and the networks they represent. This research develops a method to predict the accuracy of an AD-based classifier when applied to a new dataset, based on the difference between an already classified dataset and the …


Passive Synthetic Aperture Radar Imaging Using Commercial Ofdm Communication Networks, Jose R. Gutierrez Del Arroyo Sep 2012

Passive Synthetic Aperture Radar Imaging Using Commercial Ofdm Communication Networks, Jose R. Gutierrez Del Arroyo

Theses and Dissertations

Modern communication systems provide myriad opportunities for passive radar applications. OFDM is a popular waveform used widely in wireless communication networks today. Understanding the structure of these networks becomes critical in future passive radar systems design and concept development. This research develops collection and signal processing models to produce passive SAR ground images using OFDM communication networks. The OFDM-based WiMAX network is selected as a relevant example and is evaluated as a viable source for radar ground imaging. The monostatic and bistatic phase history models for OFDM are derived and validated with experimental single dimensional data. An airborne passive collection …


Adaptive Routing Algorithm For Priority Flows In A Network, Timothy J. Carbino Jun 2012

Adaptive Routing Algorithm For Priority Flows In A Network, Timothy J. Carbino

Theses and Dissertations

This research presents the development of an Adaptive Routing Algorithm for Priority (ARAP) flows in a Network. Devices in today's battle space require information to function. Additional bandwidth requirements for such devices place an increased burden on the already congested networks in the battle space. Some devices require real time information (high priority) and other devices will not require real time information (low priority). Existing protocols treat the network like an opaque entity and have little knowledge of user requirements. User requirement information is available in tactical networks and we can take advantage of the known requirements to better optimize …


A Novel Malware Target Recognition Architecture For Enhanced Cyberspace Situation Awareness, Thomas E. Dube Sep 2011

A Novel Malware Target Recognition Architecture For Enhanced Cyberspace Situation Awareness, Thomas E. Dube

Theses and Dissertations

The rapid transition of critical business processes to computer networks potentially exposes organizations to digital theft or corruption by advanced competitors. One tool used for these tasks is malware, because it circumvents legitimate authentication mechanisms. Malware is an epidemic problem for organizations of all types. This research proposes and evaluates a novel Malware Target Recognition (MaTR) architecture for malware detection and identification of propagation methods and payloads to enhance situation awareness in tactical scenarios using non-instruction-based, static heuristic features. MaTR achieves a 99.92% detection accuracy on known malware with false positive and false negative rates of 8.73e-4 and 8.03e-4 respectively. …


Using Reputation Based Trust To Overcome Malfunctions And Malicious Failures In Electric Power Protection Systems, Jose E. Fadul Sep 2011

Using Reputation Based Trust To Overcome Malfunctions And Malicious Failures In Electric Power Protection Systems, Jose E. Fadul

Theses and Dissertations

This dissertation advocates the use of reputation-based trust in conjunction with a trust management framework based on network flow techniques to form a trust management toolkit (TMT) for the defense of future Smart Grid enabled electric power grid from both malicious and non-malicious malfunctions. Increases in energy demand have prompted the implementation of Smart Grid technologies within the power grid. Smart Grid technologies enable Internet based communication capabilities within the power grid, but also increase the grid's vulnerability to cyber attacks. The benefits of TMT augmented electric power protection systems include: improved response times, added resilience to malicious and non-malicious …


Twitter Malware Collection System: An Automated Url Extraction And Examination Platform, Benjamin B. Kuhar Sep 2011

Twitter Malware Collection System: An Automated Url Extraction And Examination Platform, Benjamin B. Kuhar

Theses and Dissertations

As the world becomes more interconnected through various technological services and methods, the threat of malware is increasingly looming overhead. One avenue in particular that is examined in this research is the social networking service Twitter. This research develops the Twitter Malware Collection System (TMCS). This system gathers Uniform Resource Locators (URLs) posted on Twitter and scans them to determine if any are hosting malware. This scanning process is performed by a cluster of Virtual Machines (VMs) running a specified software configuration and the execution prevention system known as ESCAPE, which detects malicious code. When a URL is detected by …


A Companding Scheme With Enhanced Bit Error Rate For Peak-To-Average Power Ratio Reduction In Wireless Orthogonal Frequency Division Multiplexing Systems, Yasir Rahmatallah Aug 2011

A Companding Scheme With Enhanced Bit Error Rate For Peak-To-Average Power Ratio Reduction In Wireless Orthogonal Frequency Division Multiplexing Systems, Yasir Rahmatallah

Theses and Dissertations

Orthogonal Frequency Division Multiplexing (OFDM) is a popular multi-carrier modulation technique used in wireless communication systems due to its robustness against multipath fading. A major drawback inherited in OFDM is the non-constant envelope with high peak-to-average power ratio (PAPR). High PAPR drives the transmitter's power amplifier into saturation and causes nonlinear distortions. One way to avoid this is the use of companding to reduce the dynamic range of the time-domain OFDM signal. Usually, the PAPR is reduced at the cost of some degradation in bit error rate (BER) performance. A new scheme that utilizes traditional companding functions with side information …


Host-Based Systemic Network Obfuscation System For Windows, Kevin E. Huber Jun 2011

Host-Based Systemic Network Obfuscation System For Windows, Kevin E. Huber

Theses and Dissertations

Network traffic identifies the operating system and services of the host that created the traffic. Current obfuscation programs focus solely on the Transport and Internet layer protocols of the TCP/IP model. Few obfuscation programs were developed to run on a Windows operating system to provide host-based obfuscation. Systemic Network Obfuscation System (SNOS) was developed to provide a thorough obfuscation process for network traffic on the Windows operating system. SNOS modifies the protocols found at all layers of the TCP/IP model to effectively obfuscate the Windows operating system and services running on the host.


A Multi Agent System For Flow-Based Intrusion Detection Using Reputation And Evolutionary Computation, David Hancock Mar 2011

A Multi Agent System For Flow-Based Intrusion Detection Using Reputation And Evolutionary Computation, David Hancock

Theses and Dissertations

The rising sophistication of cyber threats as well as the improvement of physical computer network properties present increasing challenges to contemporary Intrusion Detection (ID) techniques. To respond to these challenges, a multi agent system (MAS) coupled with flow-based ID techniques may effectively complement traditional ID systems. This paper develops: 1) a scalable software architecture for a new, self-organized, multi agent, flow-based ID system; and 2) a network simulation environment suitable for evaluating implementations of this MAS architecture and for other research purposes. Self-organization is achieved via 1) a reputation system that influences agent mobility in the search for effective vantage …


Malicious And Malfunctioning Node Detection Via Observed Physical Layer Data, Tyler J. Hardy Mar 2011

Malicious And Malfunctioning Node Detection Via Observed Physical Layer Data, Tyler J. Hardy

Theses and Dissertations

There are many mechanisms that can cause inadequate or unreliable information in sensor networks. A user of the network might be interested in detecting and classifying specific sensors nodes causing these problems. Several network layer based trust methods have been developed in previous research to assess these issues; in contrast this work develops a trust protocol based on observations of physical layer data collected by the sensors. Observations of physical layer data are used for decisions and calculations, and are based on just the measurements collected by the sensors. Although this information is packaged and distributed on the network layer, …


Adaptive Quality Of Service Engine With Dynamic Queue Control, James D. Haught Mar 2011

Adaptive Quality Of Service Engine With Dynamic Queue Control, James D. Haught

Theses and Dissertations

While the current routing and congestion control algorithms in use today are often sufficient for networks with relatively static topology, these algorithms may not be sufficient for military networks where a certain level of quality of service (QoS) needs to be achieved to complete a mission. Current networking technology limits a network's ability to adapt to changes and interactions in the network, often resulting in sub-optimal performance. This research investigates the use of queue size predictions to create a network controller to optimize computer networks. These queue size predictions are made possible through the use of Kalman filters to detect …


Holistic Network Defense: Fusing Host And Network Features For Attack Classification, Jenny W. Ji Mar 2011

Holistic Network Defense: Fusing Host And Network Features For Attack Classification, Jenny W. Ji

Theses and Dissertations

This work presents a hybrid network-host monitoring strategy, which fuses data from both the network and the host to recognize malware infections. This work focuses on three categories: Normal, Scanning, and Infected. The network-host sensor fusion is accomplished by extracting 248 features from network traffic using the Fullstats Network Feature generator and from the host using text mining, looking at the frequency of the 500 most common strings and analyzing them as word vectors. Improvements to detection performance are made by synergistically fusing network features obtained from IP packet flows and host features, obtained from text mining port, processor, logon …


Covert Channels Within Irc, Wayne C. Henry Mar 2011

Covert Channels Within Irc, Wayne C. Henry

Theses and Dissertations

The exploration of advanced information hiding techniques is important to understand and defend against illicit data extractions over networks. Many techniques have been developed to covertly transmit data over networks, each differing in their capabilities, methods, and levels of complexity. This research introduces a new class of information hiding techniques for use over Internet Relay Chat (IRC), called the Variable Advanced Network IRC Stealth Handler (VANISH) system. Three methods for concealing information are developed under this framework to suit the needs of an attacker. These methods are referred to as the Throughput, Stealth, and Baseline scenarios. Each is designed for …


Routing Uavs To Co-Optimize Mission Effectiveness And Network Performance With Dynamic Programming, Spenser D. Lee Mar 2011

Routing Uavs To Co-Optimize Mission Effectiveness And Network Performance With Dynamic Programming, Spenser D. Lee

Theses and Dissertations

In support of the Air Force Research Laboratory's (AFRL) vision of the layered sensing operations center, command and control intelligence surveillance and reconnaissance (C2ISR) more focus must be placed on architectures that support information systems, rather than just the information systems themselves. By extending the role of UAVs beyond simply intelligence, surveillance, and reconnaissance (ISR) operations and into a dual-role with networking operations we can better utilize our information assets. To achieve the goal of dual-role UAVs, a concrete approach to planning must be taken. This research defines a mathematical model and a non-trivial deterministic algorithmic approach to determining UAV …


Evaluating Information Assurance Control Effectiveness On An Air Force Supervisory Control And Data Acquisition (Scada) System, Jason R. Nielsen Mar 2011

Evaluating Information Assurance Control Effectiveness On An Air Force Supervisory Control And Data Acquisition (Scada) System, Jason R. Nielsen

Theses and Dissertations

Supervisory Control and Data Acquisition (SCADA) systems are increasingly being connected to corporate networks which has dramatically expanded their attack surface to remote cyber attack. Adversaries are targeting these systems with increasing frequency and sophistication. This thesis seeks to answer the research question addressing which Information Assurance (IA) controls are most significant for network defenders and SCADA system managers/operators to focus on in order to increase the security of critical infrastructure systems against a Stuxnet-like cyber attack. This research applies the National Institute of Science and Technology (NIST) IA controls to an attack tree modeled on a remote Stuxnet-like cyber …