93,951 research outputs found

    Reverse Engineering: WiMAX and IEEE 802.16e

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    Wireless communications is part of everyday life. As it is incorporated into new products and services, it brings additional security risks and requirements. A thorough understanding of wireless protocols is necessary for network administrators and manufacturers. Though most wireless protocols have strict standards, many parts of the hardware implementation may deviate from the standard and be proprietary. In these situations reverse engineering must be conducted to fully understand the strengths and vulnerabilities of the communication medium. New 4G broadband wireless access protocols, including IEEE 802.16e and WiMAX, offer higher data rates and wider coverage than earlier 3G technologies. Many security vulnerabilities, including various Denial of Service (DoS) attacks, have been discovered in 3G protocols and the original IEEE 802.16 standard. Many of these vulnerabilities and new security flaws exist in the revised standard IEEE 802.16e. Most of the vulnerabilities already discovered allow for DoS attacks to be carried out on WiMAX networks. This study examines and analyzes a new DoS attack on IEEE 802.16e standard. We investigate how system parameters for the WiMAX Bandwidth Contention Resolution (BCR) process affect network vulnerability to DoS attacks. As this investigation developed and transitioned into analyzing hardware implementations, reverse engineering was needed to locate and modify the BCR system parameters. Controlling the BCR system parameters in hardware is not a normal task. The protocol allows only the BS to set the system parameters. The BS gives one setting of the BCR system parameters to all WiMAX clients on the network and everyone is suppose to follow these settings. Our study looks at what happens if a set of users, attackers, do not follow the BS\u27s settings and set their BCR system parameters independently. We hypothesize and analyze different techniques to do this in hardware with the goal being to replicate previous software simulations that looked at this behavior. This document details our approaches to reverse engineer IEEE 802.16e and WiMAX. Additionally, we look at network security analysis and how to design experiments to reduce time and cost. Factorial experiment design and ANOVA analysis is the solution. In using these approaches, one can test multiple factors in parallel, producing robust, repeatable and statistically significant results. By treating all other parameters as noise when testing first order effects, second and third order effects can be analyzed with less significance. The details of this type of experimental design is given along with NS-2 simulations and hardware experiments that analyze the BCR system parameters. This purpose of this paper is to serve as guide for reverse engineering network protocols and conducting network experiments. As wireless communication and network security become ubiquitous, the methods and techniques detailed in this study become increasingly important. This document can serve as a guide to reduce time and effort when reverse engineering other communication protocols and conducting network experiments

    VIRTUAL PLC PLATFORM FOR SECURITY AND FORENSICS OF INDUSTRIAL CONTROL SYSTEMS

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    Industrial Control Systems (ICS) are vital in managing critical infrastructures, including nuclear power plants and electric grids. With the advent of the Industrial Internet of Things (IIoT), these systems have been integrated into broader networks, enhancing efficiency but also becoming targets for cyberattacks. Central to ICS are Programmable Logic Controllers (PLCs), which bridge the physical and cyber worlds and are often exploited by attackers. There\u27s a critical need for tools to analyze cyberattacks on PLCs, uncover vulnerabilities, and improve ICS security. Existing tools are hindered by the proprietary nature of PLC software, limiting scalability and efficiency. To overcome these challenges, I developed a Virtual PLC Platform (VPP) for forensic analyses of ICS attacks and vulnerability identification. The VPP employs the packet replay technique, using network traffic to create a PLC template. This template guides the virtual PLC in network communication, mimicking real PLCs. A Protocol Reverse Engineering Engine (PREE) module assists in reverse-engineering ICS protocols and discovering vulnerabilities. The VPP is automated, supporting PLCs from various vendors, and eliminates manual reverse engineering. This dissertation highlights the architecture and applications of the VPP in forensic analysis, reverse engineering, vulnerability discovery, and threat intelligence gathering, all crucial to bolstering the security and integrity of critical infrastructure

    Optimization and Control of Communication Networks

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    Recently, there has been a surge in research activities that utilize the power of recent developments in nonlinear optimization to tackle a wide scope of work in the analysis and design of communication systems, touching every layer of the layered network architecture, and resulting in both intellectual and practical impacts significantly beyond the earlier frameworks. These research activities are driven by both new demands in the areas of communications and networking, and new tools emerging from optimization theory. Such tools include new developments of powerful theories and highly efficient computational algorithms for nonlinear convex optimization, as well as global solution methods and relaxation techniques for nonconvex optimization. Optimization theory can be used to analyze, interpret, or design a communication system, for both forward-engineering and reverse-engineering. Over the last few years, it has been successfully applied to a wide range of communication systems, from the high speed Internet core to wireless networks, from coding and equalization to broadband access, and from information theory to network topology models. Some of the theoretical advances have also been put into practice and started making visible impacts, including new versions of TCP congestion control, power control and scheduling algorithms in wireless networks, and spectrum management in DSL broadband access networks. Under the theme of optimization and control of communication networks, this Hot Topic Session consists of five invited talks covering a wide range of issues, including protocols, pricing, resource allocation, cross layer design, traffic engineering in the Internet, optical transport networks, and wireless networks

    Self-modifiable color petri nets for modeling user manipulation and network event handling

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    A Self-Modifiable Color Petri Net (SMCPN) which has multimedia synchronization capability and the ability to model user manipulation and network event (i.e. network congestion, etc.) handling is proposed in this paper. In SMCPN, there are two types of tokens: resource tokens representing resources to be presented and color tokens with two sub-types: one associated with some commands to modify the net mechanism in operation, another associated with a number to decide iteration times. Also introduced is a new type of resource token named reverse token that moves to the opposite direction of arcs. When user manipulation/network event occurs, color tokens associated with the corresponding interrupt handling commands will be injected into places that contain resource tokens. These commands are then executed to handle the user manipulation/network event. SMCPN has the desired general programmability in the following sense: 1) It allows handling of user manipulations or pre-specified events at any time while keeping the Petri net design simple and easy. 2) It allows the user to customize event handling beforehand. This means the system being modeled can handle not only commonly seen user interrupts (e.g. skip, reverse, freeze), the user is free to define new operations including network event handling. 3) It has the power to simulate self-modifying protocols. A simulator has been built to demonstrate the feasibility of SMCPN
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