Biblio

We study a game-theoretic model of the interactions between a Cyber-Physical System’s (CPS) operator (the defender) against an attacker who launches stepping-stone attacks to reach critical assets within the CPS. We consider that, in addition to optimally allocating its security budget to protect the assets, the defender may choose to modify the CPS through network design interventions. In particular, we propose and motivate four ways in which the defender can introduce additional nodes in the CPS: these nodes may be intended as additional safeguards, be added for functional or structural redundancies, or introduce additional functionalities in the system. We analyze the security implications of each of these design interventions, and evaluate their impacts on the security of an automotive network as our case study. We motivate the choice of the attack graph for this case study and elaborate how the parameters in the resulting security game are selected using the CVSS metrics and the ISO-26262 ASIL ratings as guidance. We then use numerical experiments to verify and evaluate how our proposed network interventions may be used to guide improvements in automotive security.

A new methodology to calculate the hysteresis induced power loss of inductor from the measured waveforms of DC-to-DC converter during the voltage conversion is presented. From this study, we find that the duty cycles (D) of the buck and boost converters used till date for inductance current calculation are not exactly equal to VOUT/VIN and 1-VIN/VOUT as the inductance change induced by the hysteresis effect cannot be neglected. Although the increase in the loading currents of the converter increases the remanence magnetization of inductor at the turn-off time (toff), this remanence magnetization is destroyed by the turbulence induced vortex current at the transistor turn-on transient. So, the core power loss of inductor increases with the loading current of the converter and becomes much larger than other power losses and cannot be neglected for the power efficiency calculation during power stage design.

Brushless synchronous generators (BSG) are typically used to produce an island network whose voltage is close to the nominal voltage of the generator. Generators are often used also in test-field applications where also zero output voltage is needed. The exciter construction and magnetic remanence may lead to a situation where the non-loaded generator terminal voltage cannot be controlled close to zero but a significant voltage is always generated because the exciter remanence. A new brushless synchronous generator excitation and de-excitation converter topology for test applications is proposed. The purpose is to achieve full voltage control from zero to nominal level without modifications to the generator. Insulated-gate bipolar transistor (IGBT) and Field-Programmable Gate Array (FPGA) technology are used to achieve the required fast and accurate control. In the work, simulation models were first derived to characterize the control performance. The proposed converter topology was then verified with the simulation model and tested empirically with a 400 kVA brushless synchronous generator. The results indicate that the exciter remanence and self-excitation can be controlled through the exciter stationary field winding when the proposed converter topology controls the field winding current. Consequently, in highly dynamical situations, the system is unaffected by mechanical stresses and wear in the generator.

Modern IoT infrastructure consists of different sub-systems, devices, applications, platforms, varied connectivity protocols with distinct operating environments scattered across different subsystems within the whole network. Each of these subsystems of the global system has its peculiar computational and security challenges. A security loophole in one subsystem has a directly negative impact on the security of the whole system. The nature and intensity of recent cyber-attacks within IoT networks have increased in recent times. Blockchain technology promises several security benefits including a decentralized authentication mechanism that addresses almost readily the challenges with a centralized authentication mechanism that has the challenges of introducing a single point of failure that affects data and system availability anytime such systems are compromised. The different design specifications and the unique functional requirements for most IoT devices require a strong yet universal authentication mechanism for multimedia data that assures an additional security layer to IoT data. In this paper, the authors propose a decentralized authentication to validate data integrity at the IoT node level. The proposed mechanism guarantees integrity, privacy, and availability of IoT node data.

The promise of access to contextual expertise, advanced security tools and an increase in staff augmentation coupled with reduced computing costs has indisputably made cloud computing a computing platform of choice, so enticing that many organizations had to migrate some if not all their services to the cloud. Identity-management-as-a-service (IdMaaS), however, is still struggling to mature due to lack of trust. Lack of trust arises from losing control over the identity information (user credentials), identity management system as well as the underlying infrastructure, raising a fear of loss of confidentiality, integrity and availability of both the identities and the identity management system. This paper recognizes the need for a trust framework comprising of both the operational and technical Frameworks as a holistic approach towards enhancing trust in IdMaaS. To this end however, only the operational Framework will form the core of this paper. The success of IdMaaS will add to the suite of other matured identity management technologies, spoiling the would-be identity service consumers with a wide choice of identity management paradigms to pick from, at the same time opening entrepreneurial opportunities to cloud players.

Digital identity is the key to the evolving digital society and economy. Since the inception of digital identity, numerous Identity Management (IDM) systems have been developed to manage digital identity depending on the requirements of the individual and that of organisations. This evolution of IDM systems has provided an incremental process leading to the granting of control of identity ownership and personal data to its user, thus producing an IDM which is more user-centric with enhanced security and privacy. A recently promising IDM known as Self-Sovereign Identity (SSI) has the potential to provide this sovereignty to the identity owner. The Sovrin Network is an emerging SSI service utility enabling self-sovereign identity for all, therefore, its assessment has to be carefully considered with reference to its architecture, working, functionality, strengths and limitations. This paper presents an analysis of the Sovrin Network based on aforementioned features. Firstly, it presents the architecture and components of the Sovrin Network. Secondly, it illustrates the working of the Sovrin Network and performs a detailed analysis of its various functionalities and metrics. Finally, based on the detailed analysis, it presents the strengths and limitations of the Sovrin Network.

Over the years, human errors have been identified as one of the most critical factors impacting cybersecurity in an organization that has had a substantial impact. The research uses recent articles published on human resources and information cybersecurity. This research focuses on the vulnerabilities and the best solution to mitigate these threats based on literature review methodology. The study also focuses on identifying the human attitude and behavior towards cybersecurity and how that would impact the organization's financial impact. With the help of the Two-factor Taxonomy of the security behavior model developed in past research, the research aims to identify the best practices and compare the best practices with that of the attitude-behavior found and matched to the model. Finally, the study would compare the difference between best practices and the current practices from the model. This would help provide the organization with specific recommendations that would help change their attitude and behavior towards cybersecurity and ensure the organization is not fearful of the cyber threat of human error threat.

Nowadays, biometric-based authentication systems are widely used. This fact has led to increased attacks on biometric data of users. Therefore, biometric template protection is sure to keep the attention of researchers for the security of the authentication systems. Many previous works proposed the biometric template protection schemes by transforming the original biometric data into a secure domain, or establishing a cryptographic key with the use of biometric data. The main purpose was that fulfill the all three requirements: cancelability, security, and performance as many as possible. In this paper, using random projection merged with fuzzy commitment, we will introduce a hybrid scheme of biometric template protection. We try to limit their own drawbacks and take full advantages of these techniques at the same time. In addition, an analysis of non-invertibility property will be exercised with regards to the use of random projection aiming at enhancing the security of the system while preserving the discriminability of the original biometric template.

With the rapid advancement of the electrical grid, substation automation systems (SASs) have been developing continuously. However, with the introduction of advanced features, such as remote control, potential cyber security threats in SASs are also increased. Additionally, crucial components in SASs, such as protection relays, usually come from third-party vendors and may not be fully trusted. Untrusted devices may stealthily perform harmful or unauthorised behaviours which could compromise or damage SASs, and therefore, bring adverse impacts to the primary plant. Thus, it is necessary to detect abnormal behaviours from an untrusted device before it brings about catastrophic impacts. Anomaly detection techniques are suitable to detect anomalies in SASs as they only bring minimal side-effects to normal system operations. Many researchers have developed various machine learning algorithms and mathematical models to improve the accuracy of anomaly detection. However, without prudent feature selection, it is difficult to achieve high accuracy when detecting attacks launched from internal trusted networks, especially for stealthy message modification attacks which only modify message payloads slightly and imitate patterns of benign behaviours. Therefore, this paper presents choices of features which improve the accuracy of anomaly detection within SASs, especially for detecting “stealthy” attacks. By including two additional features, Boolean control data from message payloads and physical values from sensors, our method improved the accuracy of anomaly detection by decreasing the false-negative rate from 25% to 5% approximately.

Many popular metrics used for the quantification of the quality or complexity of a codebase (e.g. cyclomatic complexity) were developed in the 1970s or 1980s when source code sizes were significantly smaller than they are today, and before a number of modern programming language features were introduced in different languages. Thus, the many thresholds that were suggested by researchers for deciding whether a given function is lacking in a given quality dimension need to be updated. In the pursuit of this goal, we study a number of open-source high-performance codes, each of which has been in development for more than 15 years—a characteristic which we take to imply good design to score them in terms of their source codes' quality and to relax the above-mentioned thresholds. First, we employ the LLVM/Clang compiler infrastructure and introduce a Clang AST tool to gather AST-based metrics, as well as an LLVM IR pass for those based on a source code's static call graph. Second, we perform statistical analysis to identify the reference thresholds of 22 code quality and callgraph-related metrics at a fine grained level.

Reward functions are critical hyperparameters with commercial values for individual or distributed reinforcement learning (RL), as slightly different reward functions result in significantly different performance. However, existing inverse reinforcement learning (IRL) methods can be utilized to approximate reward functions just based on collected expert trajectories through observing. Thus, in the real RL process, how to generate a polluted trajectory and perform an adversarial attack on IRL for protecting reward functions has become the key issue. Meanwhile, considering the actual RL cost, generated adversarial trajectories should be minimal and non-catastrophic for ensuring normal RL performance. In this work, we propose a novel approach to craft adversarial trajectories disguised as expert ones, for decreasing the IRL performance and realize the anti-IRL ability. Firstly, we design a reward clustering-based metric to integrate both advantages of fine- and coarse-grained IRL assessment, including expected value difference (EVD) and mean reward loss (MRL). Further, based on such metric, we explore an adversarial attack based on agglomerative nesting algorithm (AGNES) clustering and determine targeted states as starting states for reward perturbation. Then we employ the intrinsic fear model to predict the probability of imminent catastrophe, supporting to generate non-catastrophic adversarial trajectories. Extensive experiments of 7 state-of-the-art IRL algorithms are implemented on the Object World benchmark, demonstrating the capability of our proposed approach in (a) decreasing the IRL performance and (b) having minimal and non-catastrophic adversarial trajectories.

Differential privacy enables general statistical analysis of data with formal guarantees of privacy protection at the individual level. Tools that assist data analysts with utilizing differential privacy have frequently taken the form of programming languages and libraries. However, many existing programming languages designed for compositional verification of differential privacy impose significant burden on the programmer (in the form of complex type annotations). Supplementary library support for privacy analysis built on top of existing general-purpose languages has been more usable, but incapable of pervasive end-to-end enforcement of sensitivity analysis and privacy composition. We introduce DDuo, a dynamic analysis for enforcing differential privacy. DDuo is usable by non-experts: its analysis is automatic and it requires no additional type annotations. DDuo can be implemented as a library for existing programming languages; we present a reference implementation in Python which features moderate runtime overheads on realistic workloads. We include support for several data types, distance metrics and operations which are commonly used in modern machine learning programs. We also provide initial support for tracking the sensitivity of data transformations in popular Python libraries for data analysis. We formalize the novel core of the DDuo system and prove it sound for sensitivity analysis via a logical relation for metric preservation. We also illustrate DDuo's usability and flexibility through various case studies which implement state-of-the-art machine learning algorithms.

The proposed method allows us to determine the predicted value of the complex systems information security risk and its confidence interval using regression analysis and fuzzy logic in terms of the risk dependence on various factors: the value of resources, the level of threats, potential damage, the level of costs for creating and operating the system, the information resources control level.

The convergence of Internet of Things (IoT) and cloud computing is due to the practical necessity for providing broader services to extensive user in distinct environments. However, cloud computing has numerous constraints for applications that require high-mobility and high latency, notably in adversarial situations (e.g. battlefields). These limitations can be elevated to some extent, in a fog computing model because it covers the gap between remote data-center and edge device. Since, the fog nodes are usually installed in remote areas, therefore, they impose the design of fool proof safety solution for a fog-based setting. Thus, to ensure the security and privacy of fog-based environment, numerous schemes have been developed by researchers. In the recent past, Jia et al. (Wireless Networks, DOI: 10.1007/s11276-018-1759-3) designed a fog-based three-party scheme for healthcare system using bilinear. They claim that their scheme can withstand common security attacks. However, in this work we investigated their scheme and show that their scheme has different susceptibilities such as revealing of secret parameters, and fog node impersonation attack. Moreover, it lacks the anonymity of user anonymity and has inefficient login phase. Consequently, we have suggestion with some necessary guidelines for attack resilience that are unheeded by Jia et al.

Fog computing extends the capability of cloud services to support latency sensitive applications. Adding fog computing nodes in proximity to a data generation/ actuation source can support data analysis tasks that have stringent deadline constraints. We introduce a real time, security-aware scheduling algorithm that can execute over a fog environment [1 , 2] . The applications we consider comprise of: (i) interactive applications which are less compute intensive, but require faster response time; (ii) computationally intensive batch applications which can tolerate some delay in execution. From a security perspective, applications are divided into three categories: public, private and semi-private which must be hosted over trusted, semi-trusted and untrusted resources. We propose the architecture and implementation of a distributed orchestrator for fog computing, able to combine task requirements (both performance and security) and resource properties.

Quality assurance and food safety are the most problem that the consumers are special care. To solve this problem, the enterprises must improve their food supply chain management system. In addition to tracking and storing orders and deliveries, it also ensures transparency and traceability of food production and transportation. This is a big challenge that the food supply chain system using the client-server model cannot meet with the requirements. Blockchain was first introduced to provide distributed records of digital currency exchanges without reliance on centralized management agencies or financial institutions. Blockchain is a disruptive technology that can improve supply chain related transactions, enable to access data permanently, data security, and provide a distributed database. In this paper, we propose a method to design a food supply chain management system base on Blockchain technology that is capable of bringing consumers’ trust in food traceability as well as providing a favorable supply and transaction environment. Specifically, we design a system architecture that is capable of controlling and tracking the entire food supply chain, including production, processing, transportation, storage, distribution, and retail. We propose the KDTrace system model and the Channel of KDTrace network model. The Smart contract between the organizations participating in the transaction is implemented in the Channel of KDTrace network model. Therefore, our supply chain system can decrease the problem of data explosion, prevent data tampering and disclosure of sensitive information. We have built a prototype based on Hyperledger Fabric Blockchain. Through the prototype, we demonstrated the effectiveness of our method and the suitability of the use cases in a supply chain. Our method that uses Blockchain technology can improve efficiency and security of the food supply chain management system compared with traditional systems, which use a clientserver model.

An effective response against information security violations in the technical systems remains relevant challenge nowadays, when their number, complexity, and the level of possible losses are growing. The violation can be caused by the set of the intruder's consistent actions. In the area of countermeasure selection for a proactive and reactive response against security violations, there are a large number of techniques. The techniques based on graph models seem to be promising. These models allow representing the set of actions caused the violation. Their advantages include the ability to forecast violations for timely decision-making on the countermeasures, as well as the ability to analyze and consider the coverage of countermeasures in terms of steps caused the violation. The paper proposes and describes a decision support method for responding against information security violations in the technical systems based on the graph models, as well as the developed models, including the countermeasure model and the graph representing the set of actions caused the information security violation.

Purpose: Determine the main theoretical aspects of managing the resilience of an industrial enterprise in conditions of uncertainty. Method: The static control methods include the technology of the matrix aggregate computer (MAC) and the R-lenses, and the dynamic control methods - the technology based on the 4x6 matrix model. All these methods are based on the results of the theory of fuzzy sets and soft computing. Result: A comparative analysis of the resilience of 82 largest industrial enterprises in five industry classes was carried out, R-lenses were constructed for these classes, and the main factors affecting the resilience of industrial companies were evaluated. Conclusions: The central problem points in assessing and ensuring the resilience of enterprises are: a) correct modeling of external disturbances; b) ensuring the statistical homogeneity of the source data array.

Dealing with algorithms, which process large amount of similar data by using significant number of small and various sizes of memory allocation/de-allocation in a dynamic yet deterministic way, is an important issue for soft real-time systems designs. In order to improve the response time, efficiency and security of this kind of processing, we propose a software-based memory management method based on hierarchy of shared memory pools, which could be used to replace standard heap management mechanism of the operating system for some cases. Implementation of this memory management scheme can allocate memory through processing allocation/de-allocation requests of required space. Lockable implementation of this model can safely deal with the multi-threaded concurrent access. We also provide the results of experiments, according to which response time of test systems with soft time-bounded execution demand were considerably improved.

Incast traffic is a many-to-one communication pattern used in many applications, including distributed storage, web-search with partition/aggregation design pattern, and MapReduce, commonly in data centers. It is generally composed of short-lived flows that may be queued behind large flows' packets in congested switches where performance degradation is observed. Smart buffering at the switch level is sensed to mitigate this issue by automatically and dynamically adapting to traffic conditions changes in the highly dynamic data center environment. But for this dynamic and smart buffer management to become effectively beneficial for all the traffic, and especially for incast the most critical one, incast performance models that provide insights on how various factors affect it are needed. The literature lacks these types of models. The existing ones are analytical models, which are either tightly coupled with a particular protocol version or specific to certain empirical data. Motivated by this observation, we propose a machine-learning-based incast performance inference. With this prediction capability, smart buffering scheme or other QoS optimization algorithms could anticipate and efficiently optimize system parameters adjustment to achieve optimal performance. Since applying machine learning to networks managed in a distributed fashion is hard, the prediction mechanism will be deployed on an SDN control plane. We could then take advantage of SDN's centralized global view, its telemetry capabilities, and its management flexibility.

The secure functioning of automotive systems is vital to the safety of their passengers and other roadway users. One of the critical functions for safety is the controller area network (CAN), which interconnects the safety-critical electronic control units (ECUs) in the majority of ground vehicles. Unfortunately CAN is known to be vulnerable to several attacks. One such attack is the bus-off attack, which can be used to cause a victim ECU to disconnect itself from the CAN bus and, subsequently, for an attacker to masquerade as that ECU. A limitation of the bus-off attack is that it requires the attacker to achieve tight synchronization between the transmission of the victim and the attacker's injected message. In this paper, we introduce a schedule-based attack framework for the CAN bus-off attack that uses the real-time schedule of the CAN bus to predict more attack opportunities than previously known. We describe a ranking method for an attacker to select and optimize its attack injections with respect to criteria such as attack success rate, bus perturbation, or attack latency. The results show that vulnerabilities of the CAN bus can be enhanced by schedule-based attacks.

The paper considers the issue of assessing threats to information security in industrial automation and telecommunication systems in order to improve the efficiency of their security systems. A method for determining a quantitative indicator of threats is proposed, taking into account the probabilistic nature of the process of implementing negative impacts on objects of both industrial and telecommunications systems. The factors that contribute and (or) initiate them are also determined, the dependences of the formal definition of the quantitative indicator of threats are obtained. Methods for a quantitative threat assessment as well as the degree of this threat are presented in the form of a mathematical model in order to substantiate and describe the method for determining a threat to industrial automation systems. Recommendations necessary for obtaining expert assessments of negative impacts on the informatisation objects and information security systems counteracting are formulated to facilitate making decisions on the protection of industrial and telecommunication systems.

This paper presents a new framework for SATCOM jamming resiliency in the presence of a smart adversary jammer that can prioritize specific channels to attack with a non-uniform probability of distribution. We first develop a model and a defense action strategy based on a Markov decision process (MDP). We propose a greedy algorithm for the MDP-based defense algorithm's policy to optimize the expected user's immediate and future discounted rewards. Next, we remove the assumption that the user has specific information about the attacker's pattern and model. We develop a Q-learning algorithm-a reinforcement learning (RL) approach-to optimize the user's policy. We show that the Q-learning method provides an attractive defense strategy solution without explicit knowledge of the jammer's strategy. Computer simulation results show that the MDP-based defense strategies are very efficient; they offer a significant data rate advantage over the simple random hopping approach. Also, the proposed Q-learning performance can achieve close to the MDP approach without explicit knowledge of the jammer's strategy or attacking model.

Web applications have become an essential resource to access the services of diverse subjects (e.g., financial, healthcare) available on the Internet. Despite the efforts that have been made on its security, namely on the investigation of better techniques to detect vulnerabilities on its source code, the number of vulnerabilities exploited has not decreased. Static analysis tools (SATs) are often used to test the security of applications since their outcomes can help developers in the correction of the bugs they found. The conducted investigation made over SATs stated they often generate errors (false positives (FP) and false negatives (FN)), whose cause is recurrently associated with very diverse coding styles, i.e., similar functionality is implemented in distinct manners, and programming practices that create ambiguity, such as the reuse and share of variables. Based on a common practice of using multiple forms in a same webpage and its processing in a single file, we defined a use case for user login and register with six coding styles scenarios for processing their data, and evaluated the behaviour of three SATs (phpSAFE, RIPS and WAP) with them to verify and understand why SATs produce FP and FN.

Visual Question Answering (VQA) models have achieved significant success in recent times. Despite the success of VQA models, they are mostly black-box models providing no reasoning about the predicted answer, thus raising questions for their applicability in safety-critical such as autonomous systems and cyber-security. Current state of the art fail to better complex questions and thus are unable to exploit compositionality. To minimize the black-box effect of these models and also to make them better exploit compositionality, we propose a Dynamic Neural Network (DMN), which can understand a particular question and then dynamically assemble various relatively shallow deep learning modules from a pool of modules to form a network. We incorporate compositional temporal attention to these deep learning based modules to increase compositionality exploitation. This results in achieving better understanding of complex questions and also provides reasoning as to why the module predicts a particular answer. Experimental analysis on the two benchmark datasets, VQA2.0 and CLEVR, depicts that our model outperforms the previous approaches for Visual Question Answering task as well as provides better reasoning, thus making it reliable for mission critical applications like safety and security.