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Description
Access control is necessary for information assurance in many of today's applications such as banking and electronic health record. Access control breaches are critical security problems that can result from unintended and improper implementation of security policies. Security testing can help identify security vulnerabilities early and avoid unexpected expensive cost

Access control is necessary for information assurance in many of today's applications such as banking and electronic health record. Access control breaches are critical security problems that can result from unintended and improper implementation of security policies. Security testing can help identify security vulnerabilities early and avoid unexpected expensive cost in handling breaches for security architects and security engineers. The process of security testing which involves creating tests that effectively examine vulnerabilities is a challenging task. Role-Based Access Control (RBAC) has been widely adopted to support fine-grained access control. However, in practice, due to its complexity including role management, role hierarchy with hundreds of roles, and their associated privileges and users, systematically testing RBAC systems is crucial to ensure the security in various domains ranging from cyber-infrastructure to mission-critical applications. In this thesis, we introduce i) a security testing technique for RBAC systems considering the principle of maximum privileges, the structure of the role hierarchy, and a new security test coverage criterion; ii) a MTBDD (Multi-Terminal Binary Decision Diagram) based representation of RBAC security policy including RHMTBDD (Role Hierarchy MTBDD) to efficiently generate effective positive and negative security test cases; and iii) a security testing framework which takes an XACML-based RBAC security policy as an input, parses it into a RHMTBDD representation and then generates positive and negative test cases. We also demonstrate the efficacy of our approach through case studies.
ContributorsGupta, Poonam (Author) / Ahn, Gail-Joon (Thesis advisor) / Collofello, James (Committee member) / Huang, Dijiang (Committee member) / Arizona State University (Publisher)
Created2014
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Description
The purpose of this project was to implement and analyze a new proposed rootkit that claims a greater level of stealth by hiding in cache. Today, the vast majority of embedded devices are powered by ARM processors. To protect their processors from attacks, ARM introduced a hardware security extension known

The purpose of this project was to implement and analyze a new proposed rootkit that claims a greater level of stealth by hiding in cache. Today, the vast majority of embedded devices are powered by ARM processors. To protect their processors from attacks, ARM introduced a hardware security extension known as TrustZone. It provides an isolated execution environment within the embedded device that enables us to run various memory integrity and malware detection tools to identify possible breaches in security to the normal world. Although TrustZone provides this additional layer of security, it also adds another layer of complexity, and thus comes with its own set of vulnerabilities. This new rootkit identifies and exploits a cache incoherence in the ARM device as a result of TrustZone. The newly proposed rootkit, called CacheKit, takes advantage of this cache incoherence to avoid memory introspection from tools in secure world. We implement CacheKit on the i.MX53 development board, which features a single ARM Cortex A8 processor, to analyze the limitations and vulnerabilities described in the original paper. We set up the Linux environment on the computer to be able to cross-compile for the development board which will be running the FreeScale android 2.3.4 platform with a 2.6.33 Linux kernel. The project is implemented as a kernel module that once installed on the board can manipulate cache as desired to conceal the rootkit. The module exploits the fact that in TrustZone, the secure world does not have access to the normal world cache. First, a technique known as Cache-asRAM is used to ensure that the rootkit is loaded only into cache of the normal world where it can avoid detection from the secure world. Then, we employ the cache maintenance instructions and resisters provided in the cp15 coprocessor to keep the code persistent in cache. Furthermore, the cache lines are mapped to unused I/O address space so that if cache content is flushed to RAM for inspection, the data is simply lost. This ensures that even if the rootkit were to be flushed into memory, any trace of the malicious code would be lost. CacheKit prevents defenders from analyzing the code and destroys any forensic evidence. This provides attackers with a new and powerful tool that is excellent for certain scenarios that were previously thought to be secure. Finally, we determine the limitations of the prototype to determine possible areas for future growth and research into the security of networked embedded devices.
ContributorsGutierrez Barnett, Mauricio Antonio (Author) / Zhao, Ziming (Thesis director) / Doupe, Adam (Committee member) / Computer Science and Engineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-12
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Description
Affect signals what humans care about and is involved in rational decision-making and action selection. Many technologies may be improved by the capability to recognize human affect and to respond adaptively by appropriately modifying their operation. This capability, named affect-driven self-adaptation, benefits systems as diverse as learning environments, healthcare applications,

Affect signals what humans care about and is involved in rational decision-making and action selection. Many technologies may be improved by the capability to recognize human affect and to respond adaptively by appropriately modifying their operation. This capability, named affect-driven self-adaptation, benefits systems as diverse as learning environments, healthcare applications, and video games, and indeed has the potential to improve systems that interact intimately with users across all sectors of society. The main challenge is that existing approaches to advancing affect-driven self-adaptive systems typically limit their applicability by supporting the creation of one-of-a-kind systems with hard-wired affect recognition and self-adaptation capabilities, which are brittle, costly to change, and difficult to reuse. A solution to this limitation is to leverage the development of affect-driven self-adaptive systems with a manufacturing vision.

This dissertation demonstrates how using a software product line paradigm can jumpstart the development of affect-driven self-adaptive systems with that manufacturing vision. Applying a software product line approach to the affect-driven self-adaptive domain provides a comprehensive, flexible and reusable infrastructure of components with mechanisms to monitor a user’s affect and his/her contextual interaction with a system, to detect opportunities for improvements, to select a course of action, and to effect changes. It also provides a domain-specific architecture and well-documented process guidelines, which facilitate an understanding of the organization of affect-driven self-adaptive systems and their implementation by systematically customizing the infrastructure to effectively address the particular requirements of specific systems.

The software product line approach is evaluated by applying it in the development of learning environments and video games that demonstrate the significant potential of the solution, across diverse development scenarios and applications.

The key contributions of this work include extending self-adaptive system modeling, implementing a reusable infrastructure, and leveraging the use of patterns to exploit the commonalities between systems in the affect-driven self-adaptation domain.
ContributorsGonzalez-Sanchez, Javier (Author) / Burleson, Winslow (Thesis advisor) / Collofello, James (Thesis advisor) / Garlan, David (Committee member) / Sarjoughian, Hessam S. (Committee member) / Atkinson, Robert (Committee member) / Arizona State University (Publisher)
Created2016