Securing CAN-Based Cyber-Physical Systems

With the exponential growth of cyber-physical systems (CPSs), new security challenges have emerged. Various vulnerabilities, threats, attacks, and controls have been introduced for the new generation of CPS. However, there lacks a systematic review of the CPS security literature. In particular, the heterogeneity of CPS components and the diversity of CPS systems have made it difficult to study the problem with one generalized model. As the first component of this dissertation, existing research on CPS security is studied and systematized under a unified framework. Smart cars, as a CPS application, were further explored under the proposed framework and new attacks are identified and addressed. The Control Area Network (CAN bus) is a prevalent serial communication protocol adopted in industrial CPS, especially in small and large vehicles, ships, planes, and even in drones, radar systems, and submarines. Unfortunately, the CAN bus was designed without any security considerations. We then propose and demonstrate a stealthy targeted Denial of Service (DoS) attack against CAN. Experimentation shows that the attack is effective and superior to attacks of the same category due to its stealthiness and ability to avoid detection from current countermeasures. Two controls are proposed to defend against various spoofing and DoS attacks on CAN. The first one aims to minimize the attack using a mechanism called ID-Hopping so that CAN arbitration IDs are randomized so an attacker would not be able to target them. ID-Hopping raises the bar for attackers by randomizing the expected patterns in a CAN network. Such randomization hinders an attacker’s ability to launch targeted DoS attacks. Based on the evaluation on the testbed, the randomization mechanism, ID-Hopping, holds a promising solution for targeted DoS, and reverse engineering CAN IDs, and which CAN networks are most vulnerable. The second countermeasure is a novel CAN firewall that aims to prevent an attacker from launching a plethora of nontraditional attacks on CAN that existing solutions do not adequately address. The firewall is placed between a potential attacker’s node and the rest of the CAN bus. Traffic is controlled bi-directionally between the main bus and the attacker’s side so that only benign traffic can pass to the main bus. This ensures that an attacker cannot arbitrarily inject malicious traffic into the main bus. Demonstration and evaluation of the attack and firewall were conducted by a bit-level analysis, i.e., “Bit banging”, of CAN’s traffic. Results show that the firewall successfully prevents the stealthy targeted DoS attack, as well as, other recent attacks. To evaluate the proposed attack and firewall, a testbed was built that consisted of BeagleBone Black and STM32 Nucleo- 144 microcontrollers to simulate real CAN traffic. Finally, a design of an Intrusion Detection System (IDS) was proposed to complement the firewall. It utilized the proposed firewall to add situational awareness capabilities to the bus’s security posture and detect and react to attacks that might bypass the firewall based on certain rules

Securing Real-Time Internet-of-Things

Modern embedded and cyber-physical systems are ubiquitous. A large number of critical cyber-physical systems have real-time requirements (e.g., avionics, automobiles, power grids, manufacturing systems, industrial control systems, etc.). Recent developments and new functionality requires real-time embedded devices to be connected to the Internet. This gives rise to the real-time Internet-of-things (RT-IoT) that promises a better user experience through stronger connectivity and efficient use of next-generation embedded devices. However RT- IoT are also increasingly becoming targets for cyber-attacks which is exacerbated by this increased connectivity. This paper gives an introduction to RT-IoT systems, an outlook of current approaches and possible research challenges towards secure RT- IoT frameworks

Verification of information flow security in cyber-physical systems

With a growing number of real-world applications that are dependent on computation, securing the information space has become a challenge. The security of information in such applications is often jeopardized by software and hardware failures, intervention of human subjects such as attackers, incorrect design specification and implementation, other social and natural causes. Since these applications are very diverse, often cutting across disciplines a generic approach to detect and mitigate these issues is missing. This dissertation addresses the fundamental problem of verifying information security in a class of real world applications of computation, the Cyber-physical systems (CPSs). One of the motivations for this work is the lack of a unified theory to specify and verify the complex interactions among various cyber and physical processes within a CPS. Security of a system is fundamentally characterized by the way information flows within the system. Information flow within a CPS is dependent on the physical response of the system and associated cyber control. While formal techniques of verifying cyber security exist, they are not directly applicable to CPSs due to their inherent complexity and diversity. This Ph.D. research primarily focuses on developing a uniform framework using formal tools of process algebras to verify security properties in CPSs. The merits in adopting such an approach for CPS analyses are three fold- i) the physical and continuous aspects and the complex CPS interactions can be modeled in a unified way, and ii) the problem of verifying security properties can be reduced to the problem of establishing suitable equivalences among the processes, and iii) adversarial behavior and security properties can be developed using the features like compositionality and process equivalence offered by the process algebras --Abstract, page iii

CPS Attacks Mitigation Approaches on Power Electronic Systems with Security Challenges for Smart Grid Applications: A Review

This paper presents an inclusive review of the cyber-physical (CP) attacks, vulnerabilities, mitigation approaches on the power electronics and the security challenges for the smart grid applications. With the rapid evolution of the physical systems in the power electronics applications for interfacing renewable energy sources that incorporate with cyber frameworks, the cyber threats have a critical impact on the smart grid performance. Due to the existence of electronic devices in the smart grid applications, which are interconnected through communication networks, these networks may be subjected to severe cyber-attacks by hackers. If this occurs, the digital controllers can be physically isolated from the control loop. Therefore, the cyber-physical systems (CPSs) in the power electronic systems employed in the smart grid need special treatment and security. In this paper, an overview of the power electronics systems security on the networked smart grid from the CP perception, as well as then emphases on prominent CP attack patterns with substantial influence on the power electronics components operation along with analogous defense solutions. Furthermore, appraisal of the CPS threats attacks mitigation approaches, and encounters along the smart grid applications are discussed. Finally, the paper concludes with upcoming trends and challenges in CP security in the smart grid applications

Efficiency and Security of Process Transparency in Production Networks - A View of Expectations, Obstacles and Potentials

Much of the resilience and flexibility of production networks lies in the transparency of processes that allows timely perception of actual process states and adequate decisions or intervention at the proper point of the production system. Such degree of observability and permeability do, however, bear risks of malevolent tapping or interference with the information stream which, in the case of production systems, can put both business and physical processes at risk, requiring careful exploration of security threats in horizontal and vertical integration, and individual end-to-end connections likewise. Also, different levels of networked production present specific needs—high throughput and low time lag on the shop-floor level, or tolerances for confidence, gambling and bounded-rational views in cross-company relations—that may conflict with security policies. The paper presents a systematic summary of such apparently contradicting preferences, and possible approaches of reconciliation currently perceived to be relevant on various abstraction levels of production networks.status: publishe

The Use of Spider Webs as Passive Bioaerosol Collectors

In this experiment, spider webs demonstrated their suitability as passive bioaerosol collectors. For spider webs to be considered suitable passive collectors webs had to satisfy three basic conditions; (1) collection of microorganisms without discrimination based on species or size, (2) collection under variable environmental conditions, and (3) saturation avoidance in the presence of strong microbial launching sources. Four field sampling locations were used, a waste water treatment facility, a commercial garden center, a secluded state park area, and a parking garage. Microscopy cover glass slides were used as the collection instrument. The methodology assured sterility during collection and promoted in situ microbial growth and observation which were important aspects in this study. All collected spider webs revealed microbial growth from both bacteria and fungi species. This experiment paved the way for future use of webs as passive collectors of biological warfare agents and chemical warfare agents