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Intermittent random denial‐of‐service attacks (IRDoS) and deception attacks in multi‐UAV systems (MUAVs) can present significant security challenges. The intrusions of IRDoS attacks and deception attacks, respectively, can interrupt the network communication among followers and manipulate the received neighbor information with a certain probability, failing MUAVs to complete the formation task. A secure formation controller is developed for MUAVs in the presence of IRDoS and deception attacks, utilizing a distributed dynamic event‐triggered mechanism (DETM). Unlike the static event‐triggered mechanism, the triggering threshold of the DETM is adaptively adjustable, which can reduce data transmission and save network resources. The stability of the system is analyzed, and sufficient conditions are derived. Additionally, the duration and probability of successful attacks are examined. Ultimately, the simulation results showcase the efficacy and superiority of the suggested approach. [ABSTRACT FROM AUTHOR]

The problem of event‐triggered H∞$$ {H}_{\infty } $$ control for networked Takagi–Sugeno (T‐S) fuzzy system under aperiodic DoS attacks and deception attacks is investigated. First, an event generator is introduced in the Sensor‐to‐Controller channel to determine the transmission of data. At the same time, the Sensor‐to‐Controller channel is assumed to be subjected to deception attacks that are randomly distributed but not Bernoulli distributed. Next, the impact of aperiodic DoS attacks on the Controller‐to‐Actuator channel is further considered, and the DoS attack behavior is described in terms of attack period and frequency. The article designs an adaptive resilience event‐triggered mechanism (ARETM), which is aimed at circumventing the ineffective data updating in the "active" phase of the DoS attacks, thereby realizing the effective saving of communication resources and mitigating the adverse effects of DoS attacks. Then, the switched fuzzy system is established to cope with the different states of the DoS attackers. Using the piecewise Lyapunov function, a design method for the controller gains and the ARETM matrix is obtained, which allows the system to be stabilizable and obtain H∞$$ {H}_{\infty } $$ performance under the control action. Finally, the effectiveness of the ARETM‐based control strategy is confirmed by simulation experiment. [ABSTRACT FROM AUTHOR]

This work deal with the sliding mode control (SMC) issue for T-S fuzzy systems under unreliable communication environment. As a way to alleviate the transmission burden in communication networks, the round-robin protocol (RRP) is utilized for information exchange between sensors and controller. The transmitted state components via scheduling protocol may be subject to network-induced disturbances and random denial-of-service (DoS) attacks. To attenuate the adverse factors, a sliding mode controller depending on the fuzzy rules is constructed, and by employing the membership-function-dependent (MFD) technique, appropriate sufficient conditions are derived to ensure both the stochastic stability and the reachability. Finally, simulation results are presented to prove the proposed SMC strategy. [ABSTRACT FROM AUTHOR]

The controllability of complex temporal networks is one of the most important challenges of the last decade in this type of network. The main goal of controllability methods is to transport a temporal network from an initial state to the final state in a specified time with the minimum number of control nodes. Temporal complex networks have always been under various attacks, especially DoS attacks. Attacks cause the network to lose its full controllability. In this paper, the destructive effects of DoS attacks on controllability robustness have been analyzed and investigated. Then, an optimal method to repair controllability of network processes in the face of DoS attacks is proposed, which returns the network to fully controllable mode by adding the minimum number of new edges. The results demonstrate that the proposed method has increased the controllability of network robustness. Also, the proposed method has worked at a higher speed and with a lower cost (the number of new edges) than other conventional repair the controllability methods. [ABSTRACT FROM AUTHOR]

In this article, the resilient event‐triggered control issue for switched linear systems with the bounded disturbance is explored under the aperiodic denial‐of‐service (DoS) attacks. Unlike the discussions on asynchronous behavior caused by network transmission/DoS attacks, configure a copy of predictor at controller module to avert the negative impacts of asynchronous switching. Subsequently, by establishing a resilient event‐triggered strategy (RETS) to eliminate invalid sampling during DoS attacks intervals, the waste of network resources is reduced. Besides, a sufficient condition is derived to ensure the input‐to‐state stability (ISS) for the close‐loop switched systems under DoS attacks. The results indicate that the switched systems can resist a certain degree of DoS attacks under the average dwell time (ADT) constrained by DoS attacks frequency and duration. In addition, Zeno behavior is eliminated by calculating the lower bound of the triggering intervals. Finally, the availability of theoretical approach is verified through a numerical simulation. [ABSTRACT FROM AUTHOR]

This study discusses consensus tracking control problems for nonlinear stochastic multi‐agent systems under DoS attacks and deception attacks. The above attacks are respectively described as receiving duplicate data and receiving false data. In an effort to save network resources, this study proposes an appropriate dynamic event‐triggered mechanism. On this basis, a feedback controller for consensus tracking is designed. Then, a new consensus tracking criterion under dual network attacks is proposed. In addition, by selecting a new Lyapunov–Krasovskii functional and using Jesen inequality, sufficient conditions for system mean‐square stability are obtained. Finally, the efficacy of this approach is validated through a numerical example. [ABSTRACT FROM AUTHOR]

This paper studies the design of resilient distributed Nash equilibrium (NE) algorithm for second‐order multi‐agent systems in the presence of Denial‐of‐Service (DoS) attacks, which prevent information transmission in the network with limited bandwidth and transmission rate. Resilient communication schemes, integrating periodic/event‐triggered schemes and a dynamic quantized transmission method, are designed in a distributed NE seeking algorithm to ensure the convergence of agents' strategies to the NE of the game. For the designed two resilient communication schemes, the sufficient conditions for the convergence of the algorithm are established, and the tradeoff between the sampling period and the frequency and duration of DoS attacks is analyzed. Cournot competition with distributed energy resources is used as an example to verify the proposed methods. [ABSTRACT FROM AUTHOR]

This paper investigates the problem of bipartite containment control for multi‐agent systems (MASs) under denial‐of‐service (DoS) attacks with event‐triggered scheme. The DoS attacks can cause disruptions to communication channels, suspending or crashing services. In order to minimize the impact of the attacks on the control process, this paper introduces a bipartite containment control protocol with a resilient event‐triggered scheme, which enables the MASs not only to resist DoS attacks but also to optimize the utilization of resources and accomplish the control target. After considering the previous, the paper suggests a new observer to estimate the state of agents in order to cope with the unmeasurable state of MASs. Moreover, Zeno behavior avoidance is rendered more effective by the introduction of a positive constant in the event‐triggered function. At last, simulation data and results are given, thus verifying the feasibility of solving the bipartite containment problem under DoS attacks. [ABSTRACT FROM AUTHOR]

This paper investigates event-triggered H ∞ filtering for a class of discrete-time nonlinear systems subject to denial-of-service (DoS) attacks. Since the communication network in the networked systems is vulnerable to malicious cyber-attacks, this paper models DoS attacks as a Bernoulli random variable, which results in stochastic filtering error system. Besides, we use adaptive event-triggered communication to ensure that the least amount of information is transmitted over the network. For the filtering error system under the effect of event-triggered communication and DoS attacks, we provide sufficient conditions on guaranteeing the stability and prescribed H ∞ performance, where the H ∞ filter and event-triggered parameters are co-designed using the linear matrix inequality approach. Finally, two illustrative examples are provided to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

ABSTRACT This paper investigates the resilient event‐triggered control (ETC) for nonlinear multi‐agent systems in the presence of communication delays and denial‐of‐service (DoS) attacks. The communication delays and asynchronous DoS attack are considered for each communication link. Based on sampling‐receiving events and DoS attack events, flow and jump sets are formulated to describe the system's transmission time status. An independent event‐triggering mechanism (ETM) is designed for each communication link. Furthermore, a resilient control scheme is constructed in which sufficient conditions for achieving system input‐output stability are provided, including the constraints of frequency and DoS attack duration, the conditions of Lyapunov functions, and the maximally allowable transmission interval. Finally, the attitude cooperative control problem of multiple unmanned aerial vehicles (multi‐UAVs) is adopted as a simulation example. The simulation results show the effectiveness of the proposed scheme. [ABSTRACT FROM AUTHOR]

This research introduces a new adaptive control approach tailored for networked control systems, aimed at addressing the challenges of Denial of Service (DoS) attacks and round-trip time delays. Initially, a compensation mechanism based on estimated values is introduced to counter DoS attacks; subsequently, for round-trip time delay issues, a predictive delay compensation control strategy is designed. The proposed control strategy does not rely on the specific structure or a particular model of the system, but instead solely updates the controller using the system's input and output values. Moreover, we successfully demonstrate the bounded stability of the system using the direct Lyapunov method. Ultimately, the effectiveness and practicality of this method are confirmed through simulation results. [ABSTRACT FROM AUTHOR]

Abstract Denial of service (DoS) attacks occur more frequently with the progressive development of the Internet of things (IoT) and other Internet-based communication technologies. Since these technologies are deeply rooted in the individual’s comfort life, protecting the user’s privacy and security against the growing DoS attack has become a major challenge among researchers. In recent times, intrusion detection systems (IDS) have developed a vital part in ensuring security against these growing attacks. IDS is still unable to attain the optimum categorization performance due to a few bottlenecks. The speed and performance of the existing IDS are challenged by the intricacy of high-dimensional data and the efficacy of the conventional base classifiers. To tackle this aforementioned problem, this research article presents the hybrid IDS based on the combination of stacked feature selection methods such as Random Boruta Selector (RFS), Relief, Pearson coefficient (PCE) and Stacked learning classifiers (SLF). To reduce the dimension of the data features and to select the optimal feature sets, novel integration of RFS, Relief, PCE are deployed. As the final step, stacked classifiers are used for the classification of DoS attacks. All the trials in this framework were accompanied utilizing CICDDoS-2019 datasets and contrasted with the other similar models. The validation boundaries such as accuracy, precision, recall, specificity, and F1-score are used to evaluate the proposed framework. With an F1-score of 96%, accuracy of 96.5%, precision of 96.0%, and recall of 95.8%, the suggested model obtained a CICDDoS-2019 score of 96%. Compared with the other traditional classifiers, the suggested framework has produced the best classification performance in detecting the DoS attacks.

The quantitative control problem of nonlinear discrete-time systems under DoS attacks is studied in this paper. The nonlinear part of the system is approximated linearly by T-S fuzzy model. Unknown DoS attacks are defined and modeled in terms of attack frequency and attack duration. By adding dynamic system, an intermediate observer is designed to estimate the system states. Dynamic quantizers and controllers are used to quantify and control system signals in different modes, a descriptor representation form of mode-dependent closed-loop control system can be constructed. By defining the mode-dependent Lyapunov function, the design conditions of quantizers and controllers can be obtained to satisfy the system mean-square exponential stability and the desired $l_{2}-l_{\infty }$ performance. Finally, a nonlinear mass-spring-damper mechanical system is used to verify the effectiveness of the method.

Abstract Here, the issue of distributed adaptive event‐triggered fault‐tolerant cooperative control (FTCC) is studied for multiple unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) in the presence of actuator faults under denial‐of‐service attacks. To save the limited communication network resources, the distributed adaptive event‐triggered FTCC scheme is investigated for the multiple UAVs and UGVs which does not require continuous information relating to its neighbours. It is proven that the tracking errors are uniformly ultimately bounded by utilizing the Lyapunov function approach. Furthermore, the Zeno behaviour is excluded with the proposed scheme. Finally, simulation studies are provided to demonstrate the efficiency of the proposed scheme.

Summary: In this paper, a prescribed performance model‐free adaptive platooning sliding mode control (PP‐MFAP‐SMC) problem for the nonlinear vehicular platooning systems (VPSs) under denial‐of‐service (DoS) attacks is studied. Firstly, the partial form dynamic linearization (PFDL) technique is employed to convert the nonlinear VPSs into an equivalent linear data model, in which the nonlinear features of the VPSs are compressed into an unknown time‐varying pseudo gradient (PG) vector. Then, an observer is devised to acquire the estimation value of the unknown time‐varying PG vector. To lower the complication of the design, the constrained tracking error is converted into the unconstrained one. Based on which, the sliding mode control (SMC) strategy is proposed to enhance the robustness of the VPSs. Further, a PP‐MFAP‐SMC algorithm with an attack compensation mechanism is developed to ensure that the vehicular tracking errors of the position and velocity can converge to the predefined regions, respectively. Eventually, the effectiveness of the developed algorithm is demonstrated by an actual VPS with the comparisons. [ABSTRACT FROM AUTHOR]

In this article, the asynchronous control problem of switched linear systems with all unstable modes under denial‐of‐service (DoS) attacks is studied. First, the upper bound of the sampling period, which can be easily calculated based on the scenario where all modes are unstable, is obtained under a periodic sampling control strategy. Second, by constructing an appropriate discrete multiple linear quadratic Lyapunov function, an asynchronous control scheme in the form of linear matrix inequalities is devised. To ensure the stability of switched systems under DoS attacks, a sufficient condition for the total duration and frequency of DoS attacks is established. It is shown that the switched system can tolerate DoS attacks up to a certain limit while maintaining exponential stability, and this result is applicable even when all subsystems are unstable. Finally, numerical examples and a comparative study are presented to demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

Here, the issue of distributed adaptive event‐triggered fault‐tolerant cooperative control (FTCC) is studied for multiple unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) in the presence of actuator faults under denial‐of‐service attacks. To save the limited communication network resources, the distributed adaptive event‐triggered FTCC scheme is investigated for the multiple UAVs and UGVs which does not require continuous information relating to its neighbours. It is proven that the tracking errors are uniformly ultimately bounded by utilizing the Lyapunov function approach. Furthermore, the Zeno behaviour is excluded with the proposed scheme. Finally, simulation studies are provided to demonstrate the efficiency of the proposed scheme. [ABSTRACT FROM AUTHOR]

This article investigates the secure consensus control problem of positive multi‐agent systems under multiple‐mode Denial‐of‐Service (DoS) attacks. A bumpless transfer (BT) control based secure mode strategy is proposed to improve the switching transient performance due to the system being actively switched to secure mode when attack is detected. Considering possible time delays for agents dealing with the issues of DoS attacks, an asynchronous switching model is established between system models and communication topology. With the stability theory of positive systems, sufficient and necessary conditions are established to guarantee the positivity of multi‐agent systems under the secure mode strategy. Because the switching law caused by external attacks is unknown in advance, the BT control is specifically implemented through the controller gain interpolation technique. By multiple Lyapunov functions (MLFs) approach, secure consensus is achieved with a trade‐off among controller performance, attack parameters, and switching delays. Numerical examples are presented to demonstrate the effectiveness of the obtained results. [ABSTRACT FROM AUTHOR]

This paper studies the fuzzy $ H_\infty $ H ∞ control of nonlinear DC microgrids subject to the dynamic event-triggered mechanism (ETM), aperiodic DoS attacks, noises and mismatching premises. First, using the information of DC microgrid's T-S fuzzy model and aperiodic DoS attacks, a discrete-time resilient dynamic ETM is proposed, which can save constrained system resources, as well as actively exclude attack-induced dropouts and Zeno behaviour. Second, a fuzzy switched system model is built, which provides a unified platform to evaluate effects of all the affecting factors such as the dynamic ETM and DoS attacks. Third, by constructing a piecewise Lyapunov functional, criteria for exponential stability with guaranteed $ H_\infty $ H ∞ performance are obtained, and an event-triggered fuzzy injection current controller is further designed. Simulation results confirm that, in the presence of aperiodic DoS attacks and noises, the proposed controller can stabilise the nonlinear DC microgrids, while the dynamic ETM works well in reducing the triggering rate without dropouts. Tradeoffs can be made between control and communication resources, and the proposed fuzzy controller achieves shorter settling times and smaller overshoots than the robust controller. [ABSTRACT FROM AUTHOR]

This paper focuses on secure consensus for leader-following multiagent systems (MASs) modeled by partial differential equations (PDEs) under denial of service (DoS) attacks. To mitigate the negative effects of DoS attacks, which can paralyze communication and cause agents to fail to receive valid control inputs, a buffer region is established in the communication channels among agents to temporarily store messages from neighbors. Additionally, since the states of the leader and followers are not always measurable, observers are used to estimate these states. To address these challenges, this paper proposes two boundary controllers to ensure leader-following consensus in both measurable and unmeasurable states. One controller is based on original boundary information, while the other utilizes observation information from both the leader and followers. To the best of our knowledge, this is the first attempt to use buffers to solve a class of PDEs-based MASs under DoS attacks. Furthermore, the boundary control approach has the potential to significantly reduce the number of actuators required, thereby lowering control costs. Finally, we present two numerical examples to validate the feasibility of the proposed methods. • The effects of time and position on state changes are considered to better reflect agents' behaviors. • Boundary control approach reduces the quantity of actuators used with lower control costs. • Buffer is used to defend against denial of service attacks. • The proposed method guarantees leader-following consensus for observer-based multiagent systems. [ABSTRACT FROM AUTHOR]

This paper explores event-triggered model predictive control (MPC) for constrained switched systems, incorporating a buffer-based anti-attack (BBAA) approach to ensure network security. Since the system state is unknown and disturbed, an observer-based $ H_{\infty } $ H ∞ MPC approach is used to estimate the system state and suppress disturbance. Furthermore, the estimated state and control input can be optimised by minimising the performance function. Considering that the system state is subject to denial of service (DoS) attacks in the feedback channel, the BBAA approach is used to reconstruct the estimated state, thereby reducing the impact of attacks on system performance. To improve the utilisation of network resources, a set of event-triggering mechanisms (ETMs) is used. In addition, a set of matrix inequality conditions is given to constrain the gains of controllers and observers. Then, the system $ H_{\infty } $ H ∞ performance is demonstrated by applying the average dwell time (ADT) and the Lyapunov function method, and the complex coupling between model switching, DoS attacks and event-triggering is analysed. Simulation results validate the effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]

This article investigates the bipartite secure consensus of the second‐order leader‐follower multi‐agent systems (MASs) against aperiodic denial of service (DoS) attacks. First, a new dynamic event‐triggered strategy is proposed for the consensus control. Compared with the static event‐triggered strategy, the dynamic event‐triggered protocol can reduce the trigger times and save resources by introducing an internal dynamic variable. Different from the secure consensus results which only discussed the cooperative links, based on the theory of the structurally balanced graph, this article considers cooperative and antagonistic interactions among agents simultaneously for complex behaviors of them. Besides, the characteristics of the DoS attacks are analyzed in detail and the secure consensus is achieved by utilizing the Lyapunov theory and inductive methods. Finally, the Zeno behavior is excluded and the availability of the designed algorithms is demonstrated by numerical simulations. [ABSTRACT FROM AUTHOR]

This article addresses the problem of model predictive control of networked jump systems in the presence of DoS attacks and time delays. In the structural framework of the network predictive control system, we mathematically model the networked jump system by using Markov chains to describe the time delays and a polytope model to describe the jump system phenomenon, considering the properties of DoS attacks and time delays. Based on this, we propose a strategy to lessen the effect of network constraints on the control performance of the system. This strategy involves the corresponding control inputs from the control sequence for real‐time active compensation. It includes adjusting the control sequence application length variation based on the duration of the DoS attacks and time delays at each moment. In addition, we demonstrate the recursive feasibility of the control strategy and the global asymptotic stability of the control system from a theoretical perspective through the Lyapunov stability theory. Finally, the effectiveness of the proposed strategy is verified by simulation arithmetic. [ABSTRACT FROM AUTHOR]

Summary: This article focuses on a distributed optimization problem under an undirectd and connected network affected by DoS attacks. First, new event‐triggered mechanisms are developed to schedule the communication between agents. Then, an event‐based resilient distributed optimization algorithm that removes the requirement of continuous communication in the existing results is designed to achieve consensus optimization. Assisted by the design of regulator equations and the algebraic graph theory, it proves that the proposed algorithm is exponentially convergent. Moreover, Zeno behavior can be excluded by reductio ad absurdum. The simulation results validate that the proposed algorithm is effective. [ABSTRACT FROM AUTHOR]

This paper addresses the secure quasi-synchronization issue of heterogeneous complex networks (HCNs) under aperiodic denial-of-service (DoS) attacks with dynamic event-triggered impulsive scheme (ETIS). The heterogeneity of networks and the aperiodic DoS attacks, which hinder communication channels and synchronization goals, present challenges to the analysis of secure quasi-synchronization. The ETIS leverages impulsive control and dynamic event-triggered scheme (ETS) to handle the network heterogeneity and the DoS attacks. We give specific bounds on the attack duration and frequency that the network can endure, and obtain synchronization criteria that relate to event parameters, attack duration, attack frequency, and impulsive gain by the variation of parameter formula and recursive methods. Moreover, we prove that the dynamic ETS significantly reduces the controller updates, saves energy without sacrificing the system decay rate, and prevents the Zeno phenomenon. Finally, we validate our control scheme with a numerical example. • A novel dynamic event-triggered impulsive scheme that involves forced event sequence is developed. • We provide specific bounds on DoS attack duration and frequency that the network can tolerate. • This paper handles the secure quasi-synchronization of heterogeneous complex networks under DoS attacks. • An exact expression for the synchronization error bound and the system decay rate is provided. • Zeno behavior is avoided. [ABSTRACT FROM AUTHOR]

This paper is concerned with the distributed model predictive control (DMPC) for heterogeneous connected vehicle platoon (CVP) under denial-of-service (DoS) attacks. Firstly, a dynamic event-triggering mechanism (DETM) based on the information interaction between vehicles is proposed to reduce the communication and computational burdens. Due to the fact that the triggering moment for each vehicle cannot be synchronized and DoS attacks can break the communication between vehicles, a packet replenishment mechanism is designed to ensure the integrity and effectiveness of information interaction. Then, the effect of external disturbance is handled by adding robustness constraints to the DMPC algorithm. In addition, the recursive feasibility of the DMPC algorithm and input-to-state practical stability (ISPS) of the CVP control system are demonstrated. Finally, the effectiveness of the algorithm is verified by simulation and comparison results. • A general model for the longitudinal dynamics of heterogeneous vehicles with external disturbances is considered. • A secure platooning control protocol is designed for automated vehicles under DoS attacks. • A distributed model predictive control strategy is designed for each follower vehicle. • A dynamic event-triggering mechanism is designed to reduce the communication and computational burdens. [ABSTRACT FROM AUTHOR]

This paper studies the adaptive event-triggered (AET)-based path following control problem for networked autonomous vehicles subject to aperiodic denial-of-service (DoS) attacks. Firstly, considering the strong dependence between scheduling parameters, a polytopic linear parameter varying system is established to represent the nonlinear path following system. Secondly, to save limited communication bandwidth and guarantee a desired path following control performance effectively, a novel AET mechanism with nonmonotonic characteristics is designed, and a compensation strategy is presented to tackle the effect of packet losses caused by DoS attacks on the system. Thirdly, sufficient conditions are developed for the output feedback controller gain matrix and the AET mechanism weighting matrix such that the closed-loop system is guaranteed to be stable and an $H_\infty $ H ∞ performance is satisfied. Finally, simulation results verify the proposed control strategy. [ABSTRACT FROM AUTHOR]

This paper proposes a decentralized adaptive event-triggered fault-tolerant cooperative control (ET-FTCC) scheme for multiple unmanned aerial vehicles (UAVs) and unmanned ground vehicles (UGVs) with actuator faults and external disturbances under denial-of-service (DoS) attacks. The multiple UAVs and UGVs have a larger search radius, which is important in both the civilian and military domains. The different dynamics between UAVs and UGVs result in unbalanced interactions in the communication topologies, which increases the complexity of cooperative control. DoS attacks are conducted in both sensor and control channels. The dynamic models of UAVs and UGVs are introduced firstly, and the unified heterogeneous multiagent system model with actuator faults is established. The composite observer is designed to obtain the information of state and lumped disturbance, which is used to design the controller. In order to save the limited communication network resources, the event-triggered mechanism is introduced. The transformed error is presented by using the prescribed performance function (PPF). Then, the sliding-mode manifold is presented by combining the event-triggered control scheme to achieve the tracking purpose with actuator faults, external disturbances, and DoS attacks. Based on the Lyapunov function approach, the tracking errors are bounded within the prescribed boundary. Finally, the effectiveness of the proposed method is verified by qualitative analysis and quantitative analysis of the simulation results. This study can enhance the security and reliability of heterogeneous multiagent systems, providing technical support for the safe operation of unmanned systems. This paper mainly solves the FTCC problem of second-order nonlinear heterogeneous multiagent systems, and further research is needed for the FTCC problem of higher-order nonlinear heterogeneous multi-agent systems. In addition, the system may encounter multiple cyber attacks. As one of the future research works, we can extend the results of this paper to high-order nonlinear systems under multiple cyber attacks, which contain DoS attacks and deception attacks, and achieve fault-tolerant cooperative control of heterogeneous multiagent systems. [ABSTRACT FROM AUTHOR]

In today's digital world, no one and nothing is safe from potential cyberattacks. There is also no 100% protection from such attacks. Therefore, it is advisable to carry out various studies related to the effects of the different cyberattacks on the performance of the specific devices under attack. In this work, a study was carried out to determine how individual TCP DoS attacks affect the parameters of VoIP (Voice over IP) voice and video streams. For the purpose of this work, a model of a simple IP network has been created using the GNS3 IP network-modeling platform. The VoIP platform used was Asterisk Free PBX. Tools from Kali Linux were used to implement the individual TCP DoS attacks; IP-network-monitoring tools and round-trip-delay-measurement tools were also used. The proposed study is applicable to multiple VoIP platforms wherein voice and video traffic are passed/processed by the VoIP server. From the obtained results, it was found that Asterisk Free PBX is very well secured against TCP DoS attacks, which do not affect the platform performance or the parameters of the voice and video streams. The values of the observed parameters, such as jitter, packet loss, round-trip delay, etc., are very far from the maximum allowable values. We also observed a low load on the CPU and RAM of the system during the whole study. [ABSTRACT FROM AUTHOR]

In this article, the hybrid‐triggered predictive control of cyber‐physical systems (CPSs) under cyber‐attacks is researched. Firstly, considering the unpredictable state of the CPSs, an observer‐based model is constructed, and the predictor is put forward to predict state. Secondly, a hybrid‐triggered scheme is adopted to avoid unnecessary‐data transmission by introducing a hybrid switch mode. Thirdly, the deception attacks and DoS attacks are existed in sensor‐to‐observer (S‐O) and observer‐to‐controller (O‐C), separately. Two types of attack modeling are established based on their characteristics. With the proposed control method, some sufficient conditions are obtained to ensure the input‐to‐state stability (ISS) of CPSs. Finally, the results of simulation examples are received to testify the advantage of developed control strategy. [ABSTRACT FROM AUTHOR]

This research introduces a new adaptive control approach tailored for networked control systems, aimed at addressing the challenges of Denial of Service (DoS) attacks and round-trip time delays. Initially, a compensation mechanism based on estimated values is introduced to counter DoS attacks; subsequently, for round-trip time delay issues, a predictive delay compensation control strategy is designed. The proposed control strategy does not rely on the specific structure or a particular model of the system, but instead solely updates the controller using the system's input and output values. Moreover, we successfully demonstrate the bounded stability of the system using the direct Lyapunov method. Ultimately, the effectiveness and practicality of this method are confirmed through simulation results.

In today’s digital world, no one and nothing is safe from potential cyberattacks. There is also no 100% protection from such attacks. Therefore, it is advisable to carry out various studies related to the effects of the different cyberattacks on the performance of the specific devices under attack. In this work, a study was carried out to determine how individual TCP DoS attacks affect the parameters of VoIP (Voice over IP) voice and video streams. For the purpose of this work, a model of a simple IP network has been created using the GNS3 IP network-modeling platform. The VoIP platform used was Asterisk Free PBX. Tools from Kali Linux were used to implement the individual TCP DoS attacks; IP-network-monitoring tools and round-trip-delay-measurement tools were also used. The proposed study is applicable to multiple VoIP platforms wherein voice and video traffic are passed/processed by the VoIP server. From the obtained results, it was found that Asterisk Free PBX is very well secured against TCP DoS attacks, which do not affect the platform performance or the parameters of the voice and video streams. The values of the observed parameters, such as jitter, packet loss, round-trip delay, etc., are very far from the maximum allowable values. We also observed a low load on the CPU and RAM of the system during the whole study.

This paper investigates the consensus control problem for a class of nonlinear multi-agent systems (MASs) with communication link faults and denial-of-service (DoS) attacks. First, considering simultaneously the communication link faults and DoS attacks, an adaptive event-triggered control strategy of MASs is proposed based on distributed adjacency error signals, and the avoidance of the Zeno phenomenon is analyzed. In addition, the unknown nonlinear functions can be approximated by the RBF neural networks. Then, based on Lyapunov stability analysis and induction, it is proved that all signals of MASs are uniformly ultimately bounded (UUB). Finally, the effectiveness of the proposed control scheme is verified by a simulation example.

This article focuses on fixed‐time consensus of networked Euler–Lagrange systems (NELSs) over event‐based communication under denial‐of‐service (DoS) attacks. First of all, a basic fixed‐time consensus algorithm is developed for NELSs, where a general fixed‐time communication triggering scheme through error decomposition method is designed for decreasing communication frequencies while avoiding singularity. Then, to fulfil the consensus problem of NELSs in the presence of DoS attacks, a novel fixed‐time resilient algorithm is further presented by the basic algorithm, where the effective attack interval is redefined for carrying out the algorithm design. Furthermore, a hierarchical fixed‐time control framework with privacy preservation is introduced for the consensus problem of NELSs under DoS attacks. Meanwhile, a self‐triggered scheme is employed for the above algorithms to lower the update frequencies of control inputs. The stated algorithms possess a uniformly constrained upper bound on the convergence time, and are resilient as well as responsive to DOS attacks while saving control resources significantly. Finally, numerous illustrative examples are given for demonstrating the efficacy of the derived schemes. [ABSTRACT FROM AUTHOR]

This paper focuses on policy selection and scheduling of sensors and attackers in cyber-physical systems (CPSs) with multiple sensors under denial-of-service (DoS) attacks. DoS attacks have caused enormous disruption to the regular operation of CPSs, and it is necessary to assess this damage. The state estimation of the CPSs plays a vital role in providing real-time information about their operational status and ensuring accurate prediction and assessment of their security. For a multi-sensor CPS, this paper is different from utilizing robust control methods to characterize the state of the system against DoS attacks, but rather positively analyzes the optimal policy selection of the sensors and the attackers through dynamic programming ideology. To optimize the strategies of both sides, game theory is employed as a means to study the dynamic interaction that occurs between the sensors and the attackers. During the policy iterative optimization process, the sensors and attackers dynamically learn and adjust strategies by incorporating reinforcement learning. In order to explore more state information, the restriction on the set of states is relaxed, i.e., the transfer of states is not limited compulsorily. Meanwhile, the complexity of the proposed algorithm is decreased by introducing a penalty in the reward function. Finally, simulation results show that the proposed algorithm can effectively optimize policy selection and scheduling for CPSs with multiple sensors. [ABSTRACT FROM AUTHOR]

To enhance security in the semiconductor industry's globalized production, the Defense Advanced Research Projects Agency (DARPA) proposed an authentication protocol under the Supply Chain Hardware Integrity for Electronics Defense (SHIELD) program. This protocol integrates a secure hardware root-of-trust, known as a dielet, into integrated circuits (ICs). The SHIELD protocol, combined with the Advanced Encryption Standard (AES) in counter mode, named CTR-SHIELD, targets try-and-check attacks. However, CTR-SHIELD is vulnerable to desynchronization attacks on its counter blocks. To counteract this, we introduce the DTR-SHIELD protocol, where DTR stands for double counters. DTR-SHIELD addresses the desynchronization issue by altering the counter incrementation process, which previously solely relied on truncated serial IDs. Our protocol adds a new AES encryption step and requires the dielet to transmit an additional 100 bits, ensuring more robust security through active server involvement and message verification. [ABSTRACT FROM AUTHOR]

This paper investigates the consensus control problem for a class of nonlinear multi-agent systems (MASs) with communication link faults and denial-of-service (DoS) attacks. First, considering simultaneously the communication link faults and DoS attacks, an adaptive event-triggered control strategy of MASs is proposed based on distributed adjacency error signals, and the avoidance of the Zeno phenomenon is analyzed. In addition, the unknown nonlinear functions can be approximated by the RBF neural networks. Then, based on Lyapunov stability analysis and induction, it is proved that all signals of MASs are uniformly ultimately bounded (UUB). Finally, the effectiveness of the proposed control scheme is verified by a simulation example. [ABSTRACT FROM AUTHOR]