Cyber Failures Research Articles

Securing Infrared Communication in Nuclear Power Plants: Advanced Encryption for Infrared Sensor Networks.

This study enhances infrared communication security in nuclear power plants' secondary systems, addressing the risk of mechanical and cyber failures. A novel random address generator, employing an innovative S-box, was developed to secure IoT sensor data transmissions to gateway nodes, mitigating eavesdropping, interference, and replay attacks. We introduced a structured IR communication protocol, generating unique, encrypted addresses to prevent unauthorized access. Key-dependent S-boxes, based on a compound chaotic map system, significantly improved encryption, increasing data transmission randomness and uniqueness. Entropy analysis and reduced duplicated addresses confirmed the effectiveness of our method, with the Hash-CCM algorithm showing the highest entropy and fewest duplicates. Integrating advanced cryptographic techniques into IR systems significantly enhances nuclear power plants' security, contributing to the protection of critical infrastructure from cyber threats and ensuring operational integrity.

Impact of cyber failures on operation and adequacy of Multi-Microgrid distribution systems

The primary objective of this paper is to create a suitable reliability assessment framework for Cyber–Physical Multi-MicroGrid (CPMMG) distribution systems, considering the device-level failures of control and protection systems. For this purpose, the typical structure of a CPMMG distribution system with a centralized protection system is first exemplified. Then, the interdependencies between cyber and power infrastructures are investigated in such systems. Regarding the protection system, a Markov model is presented to investigate hidden failures of fault location, isolation, and service restoration processes. Possible operation modes in a CPMMG distribution system – normal, islanding, joint, and shutdown modes – are then explained and modeled. Finally, a suitable Monte Carlo simulation-based reliability assessment framework is developed to quantify well-known reliability indices. In addition, two new adequacy indices are proposed: Interrupted but Gained Compensation (IbGC) and Supplied by Expensive Resources (SbER). A comprehensive case study is conducted to reveal the salient features of the proposed framework. The result showed that the impact of cyber failures in such systems is highly dependent on the design of the cyber system. Therefore, the adverse impact of cyber failures of control and protection systems can be effectively mitigated by proper design.

Collaborative stochastic expansion planning of cyber‐physical system considering extreme scenarios

AbstractIn this paper, a collaborative stochastic expansion planning model of cyber‐physical system (CPS) with resilience constraints is proposed. The model can reduce the coupling risk and enhance the resilience under extreme scenarios, from the perspective of the structural/functional coupling between the physical and cyber systems. The model is to collaboratively optimize expansion transmission line siting, expansion communication fibre siting, and service routing distribution to minimize total investment cost. Constraints are divided into conventional constraints and resilience constraints. In the resilience constraints, the impact of cyber failures on the dispatch strategy is analyzed, and the load shedding in stochastic scenarios is limited to guarantee the resilience of the planning scheme. Particularly, to reach a stable solution for the stochastic planning, a mixed scenario set is proposed based on the probabilistic typhoon model and the complex network theory. Finally, the model is solved by the progressive hedging (PH) algorithm. The case studies of the IEEE RTS‐79 test system demonstrate that, compared with the traditional independent planning model, the model proposed in this paper performs better in limiting load loss and enhancing resilience under extreme scenarios.

Thinking in Systems, Sifting Through Simulations: A Way Ahead for Cyber Resilience Assessment

The interaction between the physical world and information technologies creates advantages and novel emerging threats. Cyber-physical systems (CPSs) result vulnerable to cyber-related disruptive scenarios, and, for some critical systems, cyber failures may have fallouts on society and environment. Traditional risk analysis in no more sufficient to deal with these problems. New techniques are gaining increasing consensus, especially those based on systems theory. In this context, the System-Theoretic Process Analysis for Security (STPA-Sec) extends the Systems-Theoretic Accident Modelling and Processes (STAMP) model considering cyber threats, and identifying unsafe and unsecure controls throughout a cyber socio-technical system. Despite its large usage as a descriptive tool, there is still limited use of STPA-Sec in (semi-)quantitative terms. This article presents System-Theoretic Process Analysis for Security with Simulations (STPA-Sec/S), a methodological interface between STPA-Sec and quantitative resilience assessment based on simulation models. The methodology is instantiated in a demonstrative case study of a water treatment plant, and its critical CPSs which may impact both community health, and environment. The obtained results show how STPA-Sec/S foster systems understanding, allow a systematic identification of its major criticalities, and the respective quantification.

Analytical reliability evaluation method of smart micro‐grids considering the cyber failures and information transmission system faults

The reliability of smart micro-grids (SMGs), as a cyber-physical system (CPS), might be influenced by cyber failures and information transmission faults. Several Monte Carlo simulation (MCS)-based approaches have been reported to assess the reliability of SMGs and smart grids. On the other hand, analytical reliability assessment methods have been presented in some research works, while the cyber system has not been concerned. However, the literature shows a research gap in developing an accurate and fast reliability evaluation method for SMGs based on the unavailability of cyber elements and information transmission faults. This article tries to fill the discussed gap by adding the analytical modelling of cyber-physical interdependencies and information transmission faults to available analytical methods, focusing on physical uncertainties. Comparing the proposed model with existing MCS-based and analytical reliability evaluation methods illustrates the advantages of this research. Test results show that less than 5.7% expected energy not supplied (EENS) error occurs by the proposed method, which would be much faster than MCS-based ones. Moreover, the sensitivity analyses highlight the impacts of the cyber network topologies on the cyber-physical interdependencies.

Optimization of decentralized control strategies of distributed resources under cyber failures in flexible distribution network

The flexible multi-state switch (FMSS) can realize the optimal control of the distribution network under normal and faulty situations. The dependence of distribution network on cyber system becomes heavier as distributed resources such as FMSS and distributed generations (DGs) integrated to the network. To reduce the operational risks under cyber failure scenarios, this paper proposes an optimization model to enable decentralized control strategies of distributed resources under cyber failures. First, the model of flexible cyber-physical distribution system is established and the coordinated control strategies of distributed resources under different operation statuses are analyzed. Then, the adaptive fuzzy-C means method and fault tree method based on consistency of failure consequences are used to cope with the uncertainties of DGs and cyber failures, respectively. On this basis, a bi-level optimization model of the decentralized control strategies of distribution resources is established to minimize the voltage deviation and load shedding. Second order cone method and heuristic algorithm are adopted for solving the optimization problem. Finally, the proposed control strategy is validated by case studies. This study is an effective operation strategy for distributed resources in flexible distribution network.© 2017 Elsevier Inc. All rights reserved.

A novel clustering-based method for reliability assessment of cyber-physical microgrids considering cyber interdependencies and information transmission errors

In recent years, the evolution of microgrids (MGs) toward a complex interacted cyber-physical system is significant, which has received much attention. Cyber-physical MGs (CPMGs) are vulnerable to various cyber-physical interdependencies mainly. Therefore, the reliability evaluation of such systems is a crucial issue. Several research works have focused on the reliability assessment of CPMGs in the literature. However, there is a research gap in developing fast and accurate models to assess the reliability of CPMGs, simultaneously considering cyber and physical failures, cyber-power interdependencies, and information transmission errors. This article aims to fill such a knowledge gap by developing a new clustering-based method to evaluate the reliability of CPMGs. The scenarios for information transmission errors are generated by the Monte Carlo simulation (MCS), besides uncertain physical parameters, e.g., the output power of renewable distributed generations (DGs). Afterward, the clustering algorithms are used to reduce the number of scenarios. In this paper, the k-means clustering algorithm has been selected to cluster the scenarios. The introduced clustering-based method is applied to a CPMG, and test results are compared to available MCS-based studies. The inaccuracy of the proposed clustering-based method is less than 3%, while its execution time is about 22 times faster than MCS-based ones. The comparative test results under various scenarios like available methods, neglecting the cyber failures and information errors illustrate the advantages of this research. The comparative test results illustrate the accuracy of the reliability calculations, while the execution time is desired.

Differentiated local controls for distributed generators in active distribution networks considering cyber failures

The dependence of distribution network operation on cyber systems becomes heavier as the amount of grid connected distributed generation (DG) continually increases in the active distribution system (ADS). In order to reduce the operational risks under cyber failure scenarios, this paper proposes an optimization model to enable differentiated local control strategies for DGs with communication failures. First, the correspondence model between cyber failure scenarios and cyber link states is established based on the failure mode effect analysis (FMEA) method. Then a bi-level multi-objective optimization model of differentiated local control strategies for DGs is proposed, which considers the uncertainties of cyber failure scenarios and the uncertainties in power generations and load demands. It aims at minimizing the operational risks including voltage deviation and overcurrent (load curtailment) situations. Interval mathematics and intelligent optimization algorithm are adopted for solving the optimization problem. Finally, a test system is established to validate the effectiveness of the proposed local control strategies. Also, the influences of cyber system topologies on the control strategies are analyzed. This study is instrumental in devising effective operational strategies for DGs in ADS.

Reliability Evaluation of Smart Microgrids Considering Cyber Failures and Disturbances under Various Cyber Network Topologies and Distributed Generation’s Scenarios

Smart microgrids (SMGs), as cyber–physical systems, are essential parts of smart grids. The SMGs’ cyber networks facilitate efficient system operation. However, cyber failures and interferences might adversely affect the SMGs. The available studies about SMGs have paid less attention to SMGs’ cyber–physical features compared to other subjects. Although a few current research works have studied the cyber impacts on SMGs’ reliability, there is a research gap about reliability evaluation simultaneously concerning all cyber failures and interferences under various cyber network topologies and renewable distributions scenarios. This article aims to fill such a gap by developing a new Monte Carlo simulation-based reliability assessment method considering cyber elements’ failures, data/information transmission errors, and routing errors under various cyber network topologies. Considering the microgrid control center (MGCC) faults in comparion to other failures and interferences is one of the major contributions of this study. The reliability evaluation of SMGs under various cyber network topologies, particularly based on an MGCC’s redundancy, highlights this research’s advantages. Moreover, studying the interactions of uncertainties for cyber systems and distributed generations (DGs) under various DG scenarios is another contribution. The proposed method is applied to a test system using actual historical data. The comparative test results illustrate the advantages of the proposed method.

Resilient Economic Control for Distributed Microgrids Under False Data Injection Attacks

With the rapid applications of communication technology, the hierarchical control of microgrids is threatened by unprecedented cyber attacks and faults. Current researches seldom study the impact on the control of cyber failures and their defense strategies. In this research, an economic control method modified from the traditional droop control is proposed. It requires distributed generators (DGs) to exchange corresponding information through a communication network, which may face potential risks of false data injection attacks (FDIAs). To tackle it, an attack-resilient method (ARM), modified from the weighted mean subsequence reduced (WMSR) algorithm, is proposed. It is proved that the successful attack-resistance and convergence performance require the communication topology to satisfy ( <b xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">r</b> +1)-robust, using the graph theory. By employing the TrueTime2.0 toolbox of MATLAB/Simulink, simulations of two microgrid test systems are performed. Results verify the feasibility and effectiveness of the proposed method on economic control under FDIAs.

Robustness improvement for cyber physical system based on an optimization model of interdependent constraints.

With the rapid development of information technology, traditional infrastructure networks have evolved into cyber physical systems (CPSs). However, this evolution has brought along with it cyber failures, in addition to physical failures, which can affect the safe and stable operation of the whole system. In light of this, in this paper, we propose an interdependence-constrained optimization model to improve the robustness of the cyber physical system. The proposed model includes not only the realistic physical law but also the interdependence between the physical network and the cyber network. However, this model is highly nonlinear and cannot be solved directly. Therefore, we transform the model into a bi-level mixed integer linear programming problem, which can be easily and effectively solved in polynomial time. We conduct the simulation based on standard Institute of Electrical and Electronics Engineers test cases and study the impact of the disaster level and coupling strength on the robustness of the whole system. The simulation results show that our proposed model can effectively improve the robustness of the cyber physical system. Moreover, we compare the performance of the power supply in different CPSs, which have different network structures of the cyber network. Our work can provide useful instructions for system operators to improve the robustness of CPSs after extreme events happen in them.

Systemic Cyber Risk and Aggregate Impacts.

With some of the largest cyber attacks occurring in recent years-from 2010 to 2019-we are only beginning to understand the full extent of cyber risk. As businesses grapple with the risks of cyber-incidents and their imperfect ability to prevent them, attention has shifted toward risk management and insurance. While there have been efforts to understand the costs of cyber attacks, the systemic risk-a result of risks spreading across interdependent systems-associated with cyber attacks remains a critical and problem in need of further study. We contribute a theoretical framework that describes systemic cyber risk as the result of cascading, common cause, or independent failures following a cyber incident. We construct a quantitative model of cascading failures to estimate the potential economic damage associated with a given cyber incident. We present an interdisciplinary approach for extending standard sector-level input-output analyses to the cyber domain, which has not been done. We estimate the aggregate losses associated with firm-level incidents, a contribution to risk analysis and computational economic modeling. We use this model to estimate the impact of potential cyber incidents and compare model results to a case with known damages. Finally, we use the model of systemic cyber failure to consider the implications on the growing cyber insurance market and the need for broader cyber policy. While we discuss the topic of systemic cyber risk, our contribution of using I/O analysis to estimate the aggregate losses from firm-level incidents is applicable across a variety of risk analysis applications from environment to health.

Component-Level Reliability Evaluation Model for Cyber Power Devices

Reliability evaluation of power components in the presence of automation devices and cyber links is critical for the improved performance of a smart grid. This work presents a model representing a cyber power component for reliability studies, incorporating interdependency and common-cause failure while reducing computational complexity. Power-component failure, automation-component failure, communication failure, communication delay, and cyberattack are incorporated to develop a comprehensive component-level reliability-evaluation model. A multistate model is proposed with 36 states for a cyber-enabled power component by integrating cyber links as a part of the smart component. Based on the power system reliability analysis, this model is reduced to a 12-state model. Finally, a two-state model is presented for its practical adaptation to specific applications. Due to the nature of the smart component, the following basic applications are considered in this work: (i) health monitoring, (ii) real-time monitoring, and (iii) actuation. A sensitivity analysis is carried out to evaluate the impact of cyber failure and cyberattacks on the reliability of the smart component. Model-reduction techniques, reliability-evaluation procedures, and example case study are provided in order to validate the proposed method.

Analytical Reliability Evaluation of Active Distribution Systems Considering Information Link Failures

With the growing study on the active distribution network, an objective and efficient reliability evaluation method for such cyber-physical systems (CPS) is urgently needed. In this paper, first considering the cyber transmission performance, a new method is proposed for efficient evaluation of cyber link validity based on frequency-time domain transformation. In order to quantify the indirect interdependencies of cyber failures, an unresponsiveness probability model for switches is established. Then, an innovative method is proposed by combining the equivalent method and the minimal path method. Finally, a test system is established to verify the effectiveness of the proposed method. This study is instrumental in informing the efficient planning of contemporary CPS-based distribution networks.

Detection of cyber cascade failure in smart grid substation using advance grey wolf optimization

This paper proposes a novel Advance Grey Wolf Optimization (AGWO) approach to detect the cyber attack and prevent its propagation to avoid cascade failure in the smart grid substation. In this method, each wireless sensor node is modeled using graph theory. Then each node is assigned with predefined weight, which gets effected during cyber intrusion. Each sensor node monitors the trust value of neighboring nodes. If trust value is equal or higher than the pre-defined value, means no intrusion. On the other hand decrease in trust value signifies that it is affected due to cyber attack. This compromised node tries to disturb the performance of other neighboring nodes. The proposed method plays a vital role to detect the suspicious nodes in less time so that cyber failure and data losses will reduce. This method considers nodes as wolves and categorizes those using trust values during cyber intrusion. The nodes having trust weight less than thepredefined value will be treated as malicious nodes and disconnected from the system. This protects the system against the impact of cyber contingency. The proposed algorithm is compared with Particle Swarm Optimization (PSO), Genetic Algorithm (GA) and Firefly Algorithms (FA). The results shows that the AGWO out performs in terms of faster detection and less data loss. The simulations are conducted on a smart grid substation with 100 sensors. MATLAB 2019 is used for programming and coding.

Evaluation method of voltage fluctuation performance considering cyber soft failure

Voltage regulation based upon cyber system has been extensively used with the development of cyber-physical system. Still, cyber failure may result in controlling failure, which inevitably has an effect on the overall voltage performance of distribution network. In order to access the influence of cyber fault on voltage regulation, a cyber system validity model considering cyber soft failure is proposed. The analytical approach of voltage fluctuation and measurement indices of voltage fluctuation are also developed. Based on simulation of IEEE 33-bus system, proposed model is proved to simulate voltage regulation process taking cyber soft failure into consideration. Each influence of different fault factors is analyzed, which provides practical technical support for the planning and operation of the distribution system. This paper provides strategies for the research into cyber fault of distribution network, which has essential significance along with follow-up value.

An Integrated Planning Approach for Distributed Generation Interconnection in Cyber Physical Active Distribution Systems

This paper proposes a cyber-physical active distribution system (CPADS) planning method, which considers the economic aspect and overall performance in the context of distributed generations (DGs) interconnection. First, the composition of CPADS is introduced for analyzing the effect of cyber system on the planning goals and constraints, based on which the dependence of the physical system on the cyber system is investigated. Then, the framework of CPADS planning is proposed by comparing it with active distribution system (ADS). Second, the planning is modeled to search for the appropriate DGs capacities, communication mode, and voltage control frequency with the constraints including performance, construction investment, and out-of-limit voltage probability, aiming at minimizing the construction and operation cost of cyber-physical systems and maximizing the DG penetration level. After that, the bi-layer multi-objective programming without considering the random failure of cyber system is adopted to derive the optimal solution set. Monte Carlo Simulation is then performed to solve for the out-of-limit voltage probability due to cyber failures, based on which the final scheme is obtained. Simulations are conducted on the modified IEEE 33-node distribution system. The results verify the effectiveness of the proposed method.

Risk-based method to secure power systems against cyber-physical faults with cascading impacts: a system protection scheme application

The utilization levels of the transmission network can be enhanced by the use of automated protection schemes that rapidly respond to disturbances. However, such corrective systems may suffer from malfunctions that have the potential to exacerbate the impact of the disturbance. This paper addresses the challenge of jointly optimizing the dispatch of generators and protection settings in this context. This requires a holistic assessment of the cyber (protection logic) and physical (network) systems, considering the failures in each part and their interplay. Special protection schemes are used as a prototypical example of such a system. An iterative optimization method is proposed that relies on power system response simulations in order to perform detailed impact assessments and compare candidate solutions. The candidate solutions are generated on the basis of a security-constrained dispatch that also secures the system against a set of cyber failure modes. A case study is developed for a generation rejection scheme on the IEEE reliability test system (RTS): candidate solutions are produced based on a mixed integer linear programming optimisation model, and loss-of-load costs are computed using a basic cascading outage algorithm. It is shown that the partial security approach is able to identify solutions that provide a good balance of operational costs and loss-of-load risks, both in a fixed dispatch and variable dispatch context.

Creating spaces of public insecurity in times of terror: The implications of code/space for urban vulnerability analyses

From data leaks of sensitive information to the degrading or halting of complete systems upon which integral societal process rely, there are daily reminders of the precariousness of networked institutions. This form of vulnerability extends beyond services to also threaten foundational values, such as privacy, movement, and free speech. Yet, given the awareness of vulnerability to cyber disruption, little is known about how massive cyber failures might disrupt the lives of ordinary people at a micro-scale. Because technology is imbued in everyday life, and people use internet systems in bundled, complex ways to accomplish a myriad of unknown activities, a complicated web of cyber-vulnerability likely exists. Thus, the goal of this paper is to explore one dimension of this vulnerability as it pertains to public security. Terrorism is predicted to remain an urban phenomenon, and terrorists are increasingly exploiting cyber-systems. The aims of terrorism to disrupt democratic systems are perfectly achieved by cyber disruption, and this paper explores how those goals were facilitated during the Boston Marathon Bombing in 2013. By drawing on interviews with public safety officials and ordinary people who relied on the internet and linked technology during that emergency, I demonstrate the complex ways that cyber-systems limited the effectiveness of public security in times of terror. The results suggest a rethinking of the social amplification of risk paradigm that dominates in risk hazards research as well as several policy interventions in security communication and information dissemination, population management during crisis, and resilience.

Sensitivity analysis of smart grids reliability due to indirect cyber-power interdependencies under various DG technologies, DG penetrations, and operation times

The cyber failures such as failures in protection and monitoring systems will not stop the operation or change the behavior of the power system instantly but will adversely affect the performance of the power system against the potential failure. Such indirect cyber-power interdependencies (ICPIs) may either intensify the probability of future failures or postpone the repercussion to the present failure of the power elements. The much less effort has been devoted in literature to investigate the ICPIs impacts, particularly in stochastic simulating space. In this paper, a novel stochastic-based reliability evaluation method which considers the ICPIs impacts under various uncertain parameters is proposed. The consideration of uncertainty regarding the renewable distributed generation (DG) units, consumption patterns, power and cyber elements, and ICPIs is one of the most important contributions of the proposed method. Further, a novel stochastic-based state upgrading is introduced to concern the ICPIs of protection and monitoring systems. By using the proposed state upgrading methodology, it is possible to evaluate the reliability of smart grid based on ICPIs by using conventional reliability evaluation methods.The proposed risk assessment methodology is applied to an actual distribution grid. The several sensitivity studies are performed to gain insight into how the penetration level of DG units under various DG technology scenarios can affect the ICPIs impacts on the risk level of smart grid. The test results show that regardless of the DG technology scenario, the ICPIs impacts of protection system vulnerabilities gradually increase while the DG penetration increases. On the contrary, the ICPIs impacts which are corresponding to the monitoring system monotonically decrease as a function of DG penetrations, and it saturates when the penetration exceeds a certain level. The test result infers that the ICPIs impacts on the risk level of smart grid are more dramatically emphasized when the extended study duration is analyzed. In fact, the ICPIs impacts increase as a function of system age, because the failure in monitoring system may accelerate the aging failures, and particularly when the system is subject to wear out period, the ICPIs impacts on the system reliability should be more concerned.