Biblio

This paper will suggest a robust method for a network layer Moving Target Defense (MTD) using symmetric packet scheduling rules. The MTD is implemented and tested on a Supervisory Control and Data Acquisition (SCADA) network testbed. This method is shown to be efficient while providing security benefits to the issues faced by the static nature of SCADA networks. The proposed method is an automated tool that may provide defense in depth when be used in conjunction with other MTDs and traditional security devices.

To improve the security of user-chosen Android screen lock patterns, we propose a novel system-guided pattern lock scheme called "SysPal" that mandates the use of a small number of randomly selected points while selecting a pattern. Users are given the freedom to use those mandated points at any position. We conducted a large-scale online study with 1,717 participants to evaluate the security and usability of three SysPal policies, varying the number of mandatory points that must be used (upon selecting a pattern) from one to three. Our results suggest that the two SysPal policies that mandate the use of one and two points can help users select significantly more secure patterns compared to the current Android policy: 22.58% and 23.19% fewer patterns were cracked. Those two SysPal policies, however, did not show any statistically significant inferiority in pattern recall success rate (the percentage of participants who correctly recalled their pattern after 24 hours). In our lab study, we asked participants to install our screen unlock application on their own Android device, and observed their real-life phone unlock behaviors for a day. Again, our lab study did not show any statistically significant difference in memorability for those two SysPal policies compared to the current Android policy.

Quantum Key Distribution (QKD) is a revolutionary technology which leverages the laws of quantum mechanics to distribute cryptographic keying material between two parties with theoretically unconditional security. Terrestrial QKD systems are limited to distances of \textbackslashtextless;200 km in both optical fiber and line-of-sight free-space configurations due to severe losses during single photon propagation and the curvature of the Earth. Thus, the feasibility of fielding a low Earth orbit (LEO) QKD satellite to overcome this limitation is being explored. Moreover, in August 2016, the Chinese Academy of Sciences successfully launched the world's first QKD satellite. However, many of the practical engineering performance and security tradeoffs associated with space-based QKD are not well understood for global secure key distribution. This paper presents several system-level considerations for modeling and studying space-based QKD architectures and systems. More specifically, this paper explores the behaviors and requirements that researchers must examine to develop a model for studying the effectiveness of QKD between LEO satellites and ground stations.

The wide-spreading mobile malware has become a dreadful issue in the increasingly popular mobile networks. Most of the mobile malware relies on network interface to coordinate operations, steal users' private information, and launch attack activities. In this paper, we propose TextDroid, an effective and automated malware detection method combining natural language processing and machine learning. TextDroid can extract distinguishable features (n-gram sequences) to characterize malware samples. A malware detection model is then developed to detect mobile malware using a Support Vector Machine (SVM) classifier. The trained SVM model presents a superior performance on two different data sets, with the malware detection rate reaching 96.36% in the test set and 76.99% in an app set captured in the wild, respectively. In addition, we also design a flow header visualization method to visualize the highlighted texts generated during the apps' network interactions, which assists security researchers in understanding the apps' complex network activities.

The term lateral pressure refers to any tendency (or propensity) of states, firms, and other entities to expand their activities and exert influence and control beyond their established boundaries, whether for economic, political, military, scientific, religious, or other purposes. Framed by Robert C. North and Nazli Choucri, the theory addresses the sources and consequences of such a tendency. This chapter presents the core features—assumptions, logic, core variables, and dynamics—and summarizes the quantitative work undertaken to date. Some aspects of the theory analysis are more readily quantifiable than others. Some are consistent with conventional theory in international relations. Others are based on insights and evidence from other areas of knowledge, thus departing from tradition in potentially significant ways. Initially applied to the causes of war, the theory focuses on the question of: Who does what, when, how, and with what consequences? The causal logic in lateral pressure theory runs from the internal drivers (i.e., the master variables that shape the profiles of states) through the intervening variables (i.e., aggregated and articulated demands given prevailing capabilities), and the outcomes often generate added complexities. To the extent that states expand their activities outside territorial boundaries, driven by a wide range of capabilities and motivations, they are likely to encounter other states similarly engaged. The intersection among spheres of influence is the first step in complex dynamics that lead to hostilities, escalation, and eventually conflict and violence. The quantitative analysis of lateral pressure theory consists of six distinct phases. The first phase began with a large-scale, cross-national, multiple equation econometric investigation of the 45 years leading to World War I, followed by a system of simultaneous equations representing conflict dynamics among competing powers in the post–World War II era. The second phase is a detailed econometric analysis of Japan over the span of more than a century and two World Wars. The third phase of lateral pressure involves system dynamics modeling of growth and expansion of states from 1970s to the end of the 20th century and explores the use of fuzzy logic in this process. The fourth phase focuses on the state-based sources of anthropogenic greenhouse gases to endogenize the natural environment in the study of international relations. The fifth phase presents a detailed ontology of the driving variables shaping lateral pressure and their critical constituents in order to (a) frame their interconnections, (b) capture knowledge on sustainable development, (c) create knowledge management methods for the search, retrieval, and use of knowledge on sustainable development and (d) examine the use of visualization techniques for knowledge display and analysis. The sixth, and most recent, phase of lateral pressure theory and empirical analysis examines the new realities created by the construction of cyberspace and interactions with the traditional international order.

Modern vehicles are opening up, with wireless interfaces such as Bluetooth integrated in order to enable comfort and safety features. Furthermore a plethora of aftermarket devices introduce additional connectivity which contributes to the driving experience. This connectivity opens the vehicle to potentially malicious attacks, which could have negative consequences with regards to safety. In this paper, we survey vehicles with Bluetooth connectivity from a threat intelligence perspective to gain insight into conditions during real world driving. We do this in two ways: firstly, by examining Bluetooth implementation in vehicles and gathering information from inside the cabin, and secondly, using war-nibbling (general monitoring and scanning for nearby devices). We find that as the vehicle age decreases, the security (relatively speaking) of the Bluetooth implementation increases, but that there is still some technological lag with regards to Bluetooth implementation in vehicles. We also find that a large proportion of vehicles and aftermarket devices still use legacy pairing (and are therefore more insecure), and that these vehicles remain visible for sufficient time to mount an attack (assuming some premeditation and preparation). We demonstrate a real-world threat scenario as an example of the latter. Finally, we provide some recommendations on how the security risks we discover could be mitigated.

The concept of Extension Headers, newly introduced with IPv6, is elusive and enables new types of threats in the Internet. Simply dropping all traffic containing any Extension Header - a current practice by operators-seemingly is an effective solution, but at the cost of possibly dropping legitimate traffic as well. To determine whether threats indeed occur, and evaluate the actual nature of the traffic, measurement solutions need to be adapted. By implementing these specific parsing capabilities in flow exporters and performing measurements on two different production networks, we show it is feasible to quantify the metrics directly related to these threats, and thus allow for monitoring and detection. Analysing the traffic that is hidden behind Extension Headers, we find mostly benign traffic that directly affects end-user QoE: simply dropping all traffic containing Extension Headers is thus a bad practice with more consequences than operators might be aware of.

With the fast development of autonomous driving and vehicular communication technologies, intelligent transportation systems that are based on VANET (Vehicular Ad-Hoc Network) have shown great promise. For instance, through V2V (Vehicle-to-Vehicle) and V2I (Vehicle-to-Infrastructure) communication, intelligent intersections allow more fine-grained control of vehicle crossings and significantly enhance traffic efficiency. However, the performance and safety of these VANET-based systems could be seriously impaired by communication delays and packet losses, which may be caused by network congestion or by malicious attacks that target communication timing behavior. In this paper, we quantitatively model and analyze some of the timing and security issues in transportation networks with VANET-based intelligent intersections. In particular, we demonstrate how communication delays may affect the performance and safety of a single intersection and of multiple interconnected intersections, and present our delay-tolerant intersection management protocols. We also discuss the issues of such protocols when the vehicles are non-cooperative and how they may be addressed with game theory.

We present a binary static analysis approach to detect intelligent electronic device (IED) malware based on the time requirements of electrical substations. We explore graph theory techniques to model the timing performance of an IED executable. Timing performance is subsequently used as a metric for IED malware detection. More specifically, we perform a series of steps to reduce a part of the IED malware detection problem into a classical problem of graph theory, namely finding single-source shortest paths on a weighted directed acyclic graph (DAG). Shortest paths represent execution flows that take the longest time to compute. Their clock cycles are examined to determine if they violate the real-time nature of substation monitoring and control, in which case IED malware detection is attained. We did this work with particular reference to implementations of protection and control algorithms that use the IEC 61850 standard for substation data representation and network communication. We tested our approach against IED exploits and malware, network scanning code, and numerous malware samples involved in recent ICS malware campaigns.

In the cloud computing era, in order to avoid computational burdens, many organizations tend to outsource their computations to third-party cloud servers. In order to protect service quality, the integrity of computation results need to be guaranteed. In this paper, we develop a game theoretic framework which helps the outsourcer to maximize its payoff while ensuring the desired level of integrity for the outsourced computation. We define two Stackelberg games and analyze the optimal setting's sensitivity for the parameters of the model.

Due to the user-interface limitations of wearable devices, voice-based interfaces are becoming more common; speaker recognition may then address the authentication requirements of wearable applications. Wearable devices have small form factor, limited energy budget and limited computational capacity. In this paper, we examine the challenge of computing speaker recognition on small wearable platforms, and specifically, reducing resource use (energy use, response time) by trimming the input through careful feature selections. For our experiments, we analyze four different feature-selection algorithms and three different feature sets for speaker identification and speaker verification. Our results show that Principal Component Analysis (PCA) with frequency-domain features had the highest accuracy, Pearson Correlation (PC) with time-domain features had the lowest energy use, and recursive feature elimination (RFE) with frequency-domain features had the least latency. Our results can guide developers to choose feature sets and configurations for speaker-authentication algorithms on wearable platforms.

Software security is an important aspect of ensuring software quality. The goal of this study is to help developers evaluate software security using traceable patterns and software metrics during development. The concept of traceable patterns is similar to design patterns but they can be automatically recognized and extracted from source code. If these patterns can better predict vulnerable code compared to traditional software metrics, they can be used in developing a vulnerability prediction model to classify code as vulnerable or not. By analyzing and comparing the performance of traceable patterns with metrics, we propose a vulnerability prediction model. This study explores the performance of some code patterns in vulnerability prediction and compares them with traditional software metrics. We use the findings to build an effective vulnerability prediction model. We evaluate security vulnerabilities reported for Apache Tomcat, Apache CXF and three stand-alone Java web applications. We use machine learning and statistical techniques for predicting vulnerabilities using traceable patterns and metrics as features. We found that patterns have a lower false negative rate and higher recall in detecting vulnerable code than the traditional software metrics.

Security in smartphones has become one of the major concerns, with prolific growth in its usage scenario. Many applications are available for Android users to protect their applications and data. But all these security applications are not easily accessible for persons with disabilities. For persons with color blindness, authentication mechanisms pose user interface related issues. Color blind users find the inaccessible and complex design in the interface difficult to access and interpret mobile locks. This paper focuses on a novel method for providing color and touch sensitivity based dot pattern lock. This Model automatically replaces the existing display style of a pattern lock with a new user preferred color combination. In addition Pressure Gradient Input (PGI) has been incorporated to enhance authentication strength. The feedback collected from users shows that this accessible security application is easy to use without any major access barrier.

Increasing interest in cyber-physical systems with integrated computational and physical capabilities that can interact with humans can be identified in research and practice. Since these systems can be classified as safety- and security-critical systems the need for safety and security assurance and certification will grow. Moreover, these systems are typically characterized by fragmentation, interconnectedness, heterogeneity, short release cycles, cross organizational nature and high interference between safety and security requirements. These properties combined with the assurance of compliance to multiple standards, carrying out certification and re-certification, and the lack of an approach to model, document and integrate safety and security requirements represent a major challenge. In order to address this gap we developed a domain agnostic approach to model security and safety requirements in an integrated view to support certification processes during design and run-time phases of cyber-physical systems.

There has been increasing interest in adopting BlockChain (BC), that underpins the crypto-currency Bitcoin, in Internet of Things (IoT) for security and privacy. However, BCs are computationally expensive and involve high bandwidth overhead and delays, which are not suitable for most IoT devices. This paper proposes a lightweight BC-based architecture for IoT that virtually eliminates the overheads of classic BC, while maintaining most of its security and privacy benefits. IoT devices benefit from a private immutable ledger, that acts similar to BC but is managed centrally, to optimize energy consumption. High resource devices create an overlay network to implement a publicly accessible distributed BC that ensures end-to-end security and privacy. The proposed architecture uses distributed trust to reduce the block validation processing time. We explore our approach in a smart home setting as a representative case study for broader IoT applications. Qualitative evaluation of the architecture under common threat models highlights its effectiveness in providing security and privacy for IoT applications. Simulations demonstrate that our method decreases packet and processing overhead significantly compared to the BC implementation used in Bitcoin.

The traditional physical power grid is evolving into a cyber-physical Smart Grid (SG) that links the cyber communication and computational elements with the physical control functions to dynamically integrate varied and geographically distributed energy producers/consumers. In the SG, the cyber elements of Wide Area Measurement Systems (WAMS) are deployed to provide the critical monitoring of the state of power transmission and distribution to accomplish real-time control of the grid. Unfortunately, the increasing adoption of such computing/communication cyber-technologies essential to providing the SG operations also opens the risk of the SG being vulnerable to cyberattacks. In particular, attacks such as Denial-of-Service (DoS) and Distributed DoS (DDoS) are of primary concern for WAMS where such attacks can compromise its safety-critical accuracy and responsiveness characteristics. To prevent DoS/DDoS attacks at the transport and application layer from affecting the WAMS operations, we propose a proactive and robust extension of the Multipath-TCP (MPTCP) transportation protocol that mitigates such attacks by using a novel stream hopping MPTCP mechanism, termed as MPTCP-H. The proposed MPTCP-H hides the open port numbers of the connection from an attacker by renewing (over time) the subflows over new port numbers without perturbing the WAMS data traffic. Our results demonstrate MPTCP-H to be both effective and efficient (for reduced latency and congestion), and also applicable to the communication frameworks of other similar Critical Infrastructures.

SDN networks rely mainly on a set of software defined modules, running on generic hardware platforms, and managed by a central SDN controller. The tight coupling and lack of isolation between the controller and the underlying host limit the controller resilience against host-based attacks and failures. That controller is a single point of failure and a target for attackers. ``Linux-containers'' is a successful thin virtualization technique that enables encapsulated, host-isolated execution-environments for running applications. In this paper we present PAFR, a controller sandboxing mechanism based on Linux-containers. PAFR enables controller/host isolation, plug-and-play operation, failure-and-attack-resilient execution, and fast recovery. PAFR employs and manages live remote checkpointing and migration between different hosts to evade failures and attacks. Experiments and simulations show that the frequent employment of PAFR's live-migration minimizes the chance of successful attack/failure with limited to no impact on network performance.

A long time ago Industrial Control Systems were in a safe place due to the use of proprietary technology and physical isolation. This situation has changed dramatically and the systems are nowadays often prone to severe attacks executed from remote locations. In many cases, intrusions remain undetected for a long time and this allows the adversary to meticulously prepare an attack and maximize its destructiveness. The ability to detect an attack in its early stages thus has a high potential to significantly reduce its impact. To this end, we propose a holistic, multi-layered, security monitoring and mitigation framework spanning the physical- and cyber domain. The comprehensiveness of the approach demands for scalability measures built-in by design. In this paper we present how scalability is addressed by an architecture that enforces geographically decentralized data reduction approaches that can be dynamically adjusted to the currently perceived context. A specific focus is put on a robust and resilient solution to orchestrate dynamic configuration updates. Experimental results based on a prototype implementation show the feasibility of the approach.

The importance of Networked Control Systems (NCS) is steadily increasing due to recent trends such as smart factories. Correct functionality of such NCS needs to be protected as malfunctioning systems could have severe consequences for the controlled process or even threaten human lives. However, with the increase in NCS, also attacks targeting these systems are becoming more frequent. To mitigate attacks that utilize captured sensor data in an NCS, transferred data needs to be protected. While using well-known methods such as Transport Layer Security (TLS) might be suitable to protect the data, resource constraint devices such as sensors often are not powerful enough to perform the necessary cryptographic operations. Also, as we will show in this paper, applying simple encryption in an NCS may enable easy Denial-of-Service (DoS) attacks by attacking single bits of the encrypted data. Therefore, in this paper, we present a hardware-based approach that enables sensors to perform the necessary encryption while being robust against (injected) bit failures.

In this paper, we describe an efficient methodology to guide investigators during network forensic analysis. To this end, we introduce the concept of core attack graph, a compact representation of the main routes an attacker can take towards specific network targets. Such compactness allows forensic investigators to focus their efforts on critical nodes that are more likely to be part of attack paths, thus reducing the overall number of nodes (devices, network privileges) that need to be examined. Nevertheless, core graphs also allow investigators to hierarchically explore the graph in order to retrieve different levels of summarised information. We have evaluated our approach over different network topologies varying parameters such as network size, density, and forensic evaluation threshold. Our results demonstrate that we can achieve the same level of accuracy provided by standard logical attack graphs while significantly reducing the exploration rate of the network.

Vehicular Ad-Hoc Network (VANET) is a form of Peer-to-Peer (P2P) wireless communication between vehicles, which is characterized by the high mobility. In practice, VANET can be utilized to cater connections via multi-hop communication between vehicles to provide traffic information seamlessly, such as traffic jam and traffic accident, without the need of dedicated centralized infrastructure. Although dedicated infrastructures may also be involved in VANET, such as Road Side Units (RSUs), most of the time VANET relies solely on Vehicle-to-Vehicle (V2V) communication, which makes it vulnerable to several potential attacks in P2P based communication, as there are no trusted authorities that provide authentication and security. One of the potential threats is a Sybil attack, wherein an adversary uses a considerable number of forged identities to illegitimately infuse false or biased information which may mislead a system into making decisions benefiting the adversary. Avoiding Sybil attacks in VANET is a difficult problem, as there are typically no trusted authorities that provide cryptographic assurance of Sybil resilience. This paper presents a technique to detect and mitigate Sybil attacks, which requires no dedicated infrastructure, by utilizing just V2V communication. The proposed method work based on underlying assumption that says the mobility of vehicles in high vehicle density and the limited transmission power of the adversary creates unique groups of vehicle neighbors at a certain time point, which can be calculated in a statistical fashion providing a temporal and spatial analysis to verify real and impersonated vehicle identities. The proposed method also covers the mitigation procedures to create a trust model and announce neighboring vehicles regarding the detected tempered identities in a secure way utilizing Diffie-Hellman key distribution. This paper also presents discussions concerning the proposed approach with regard to benefits and drawbacks of sparse road condition and other potential threats.

Software Defined Networking (SDN) is an emerging paradigm that changes the way networks are managed by separating the control plane from data plane and making networks programmable. The separation brings about flexibility, automation, orchestration and offers savings in both capital and operational expenditure. Despite all the advantages offered by SDN it introduces new threats that did not exist before or were harder to exploit in traditional networks, making network penetration potentially easier. One of the key threat to SDN is the authentication and authorisation of network applications that control network behaviour (unlike the traditional network where network devices like routers and switches are autonomous and run proprietary software and protocols to control the network). This paper proposes a mechanism that helps the control layer authenticate network applications and set authorisation permissions that constrict manipulation of network resources.

We propose an approach to enforce security in disruption- and delay-tolerant networks (DTNs) where long delays, high packet drop rates, unavailability of central trusted entity etc. make traditional approaches unfeasible. We use trust model based on subjective logic to continuously evaluate trustworthiness of security credentials issued in distributed manner by network participants to deal with absence of centralised trusted authorities.

Mobile devices offer a convenient way of accessing our digital lives and many of those devices hold sensitive data that needs protecting. Mobile and wireless communications networks, combined with cloud computing as Mobile Cloud Computing (MCC), have emerged as a new way to provide a rich computational environment for mobile users, and business opportunities for cloud providers and network operators. It is the convenience of the cloud service and the ability to sync across multiple platforms/devices that has become the attraction to cloud computing. However, privacy, security and trust issues may still be a barrier that impedes the adoption of MCC by some undecided potential users. Those users still need to be convinced of the security of mobile devices, wireless networks and cloud computing. This paper is the result of a comprehensive review of one typical secure measure-authentication methodology research, spanning a period of five years from 2012–2017. MCC capabilities for sharing distributed resources is discussed. Authentication in MCC is divided in to two categories and the advantages of one category over its counterpart are presented, in the process of attempting to identify the most secure authentication scheme.

The advancement in technology has changed how people work and what software and hardware people use. From conventional personal computer to GPU, hardware technology and capability have dramatically improved so does the operating systems that come along. Unfortunately, current industry practice to compare OS is performed with single perspective. It is either benchmark the hardware level performance or performs penetration testing to check the security features of an OS. This rigid method of benchmarking does not really reflect the true performance of an OS as the performance analysis is not comprehensive and conclusive. To illustrate this deficiency, the study performed hardware level and operational level benchmarking on Windows XP, Windows 7 and Windows 8 and the results indicate that there are instances where Windows XP excels over its newer counterparts. Overall, the research shows Windows 8 is a superior OS in comparison to its predecessors running on the same hardware. Furthermore, the findings also show that the automated benchmarking tools are proved less efficient benchmark systems that run on Windows XP and older OS as they do not support DirectX 11 and other advanced features that the hardware supports. There lies the need to have a unified benchmarking approach to compare other aspects of OS such as user oriented tasks and security parameters to provide a complete comparison. Therefore, this paper is proposing a unified approach for Operating System (OS) comparisons with the help of a Windows OS case study. This unified approach includes comparison of OS from three aspects which are; hardware level, operational level performance and security tests.