Frequency Of Denial-of-service Attacks Research Articles

Stabilization of Networked Switched Systems Under DoS Attacks.

This article studies the stability issue of networked switched systems (NSSs) under denial-of-service (DoS) attacks. To address this issue, the derived limitations imposed on both the frequency of DoS attacks on each subsystem and the upper limit of attack duration that each subsystem can tolerate are mode-dependent, which is more efficient and flexible than the current results for NSSs. Moreover, we reveal the relationship between the upper bound of the average maximum tolerable attack duration associated with the corresponding subsystem and the actual mode-dependent average dwell time. Furthermore, we identify that the total tolerable DoS attack duration as a percentage of the system runtime in this article can be higher than existing results. Finally, an example is given to demonstrate the effectiveness of our work.

Secure Consensus Control of Multiagent Systems Under DoS Attacks: A Switching-Scheme-Based Active Defense Method.

This article studies the secure consensus control problem of multiagent systems (MASs) with a nonzero input leader subject to denial-of-service (DoS) attacks. The introduction of backup topologies makes it possible for MASs to actively defend against DoS attacks. Subsequently, a novel active defense method consisting of two types of state observers, an adaptive topology switching mechanism, and switching controllers is proposed, which can ensure the leader-follower bound consensus even if DoS attacks hinder the interaction between agents. Within such a defense framework, the switching mechanism, driven by the predefined performance index and designed monitoring function, can automatically search for a healthy communication graph among backup topologies. Concurrently, the observer-based switching control strategy will be modified to match the corresponding topology, in which the universal observer and controller parameters in different topologies are obtained by solving linear matrix inequalities. It should be highlighted that the developed defense scheme not only removes the limitations of existing results on the duration and frequency of DoS attacks but also ensures the same upper bound of consensus error before and after DoS attacks. Finally, several simulation examples for different systems illustrate the efficiency and superiority of the theoretical results.

Distributed consensus of heterogeneous switched nonlinear multiagent systems with input quantization and DoS attacks

In this paper, the consensus tracking control problem is investigated for a class of heterogeneous switched nonlinear multiagent systems (MASs) with input quantization under denial-of-service (DoS) attacks, where first-order agents and second-order agents exist simultaneously, and each agent shows the switching characteristic. Due to the prevalence of DoS attacks in communication channels, a DoS attack model is constructed in this study, and the upper bounds on the duration and frequency of DoS attacks are given. Meanwhile, taking the chattering phenomena of control inputs into account, a hysteresis quantizer is introduced to overcome the issue of the undesirable input chattering. Hence, a new anti-attack distributed consensus protocol is developed such that MASs with input quantization can effectively resist the impact of DoS attacks. Based on the Lyapunov stability theory, the boundedness of all signals in the closed-loop system is verified and the consensus target can be achieved. Finally, the effectiveness of the proposed control scheme is demonstrated by two simulation examples.

Stability of networked switched systems in the presence of denial‐of‐service attacks

AbstractThis article is concerned with the stability issue of networked switched systems which consist of only unstable subsystems subject to Denial of Service (DoS) attacks. The stability analysis of networked switched systems in the presence of DoS attacks under state‐dependent switching is first presented. It is shown that the derived restrictions which differ from those in the existing work are imposed on DoS attack model. Specifically, the proposed conditions to characterize the duration and frequency of DoS attacks are state‐dependent and mode‐dependent. As a result, the ratio of total duration of DoS attack to the operating time of switched systems is higher than the previous literature. Furthermore, our result is extended to the stability of networked switched affine systems in the presence of DoS attacks. In the end, two simulation examples are given to demonstrate the effectiveness of our work.

Dynamic event-Based resilient consensus of networked lagrangian systems under DoS attacks

In this paper, the dynamic event-based resilient consensus control of the multiple networked Euler-Lagrangian (E-L) systems under the Denial of Service (DoS) attacks is considered. Compared with linear cyber-physical systems, nonlinear networked E-L systems are more complex and closer to actual mechanical systems. For the situation where the topology is a strongly connected directed topology, a controller based on a dynamic event-trigger mechanism is designed to achieve consensus control for the networked E-L system in the absence of DoS attacks. Sufficient conditions are presented, which can guarantee the closed-loop system be stable. Then the resilient consensus problem of event-based controllers under energy-constrained DoS attacks is analyzed. The conditions related to the duration and frequency of DoS attacks are given. Zeno behavior is proved does not exist in the proposed control scheme. Finally, some numerical simulation results are given for verifying the theoretical results.

Resilient control for T-S fuzzy systems with multiple transmission channels under asynchronous denial-of-Service attacks

This paper investigates the resilient control problem of the T-S fuzzy system with multiple transmission channels under asynchronous denial-of-service (DoS) attacks. A part of the transmission channels are chosen as ones corresponding to the premise variables of the T-S fuzzy system. The considered asynchronous DoS attacks occur on the sensor-to-controller transmission channels, which may DoS attacks cause the system state to be unstable. The stability of the T-S fuzzy system under random DoS attack mode is considered, including the influence of the premise variables attacked. A class of parallel distributed compensation controllers are proposed, which adopts the strategy of discarding the attacked channels information. By using a piecewise Lyapunov function method and a class of linear matrix inequalities, the system stability sufficient conditions related to the duration and frequency of DoS attacks on the transmission channels are presented. Compared with the existing method, the more general relationship between premise variables and transmission channels are considered in this paper. Finally, a numerical example is used to illustrate the effectiveness of the proposed scheme.

Fully Distributed Resilient Cooperative Control of Vehicular Platoon Systems Under DoS Attacks

This letter is concerned with distributed resilient platoon control of multiple vehicles subject to denial-of-service (DoS) attacks. In order to accommodate the effects of DoS attacks, a fully resilient distributed control strategy is presented by designing an adaptive control gain, where any global information of communication topology is no longer required. Then, the conditions of time duration rates and frequency of DoS attacks on stability of vehicular platoons can be characterized. Finally, a numerical simulation example is given to validate the obtained results.

Distributed Secure Consensus Control With Event-Triggering for Multiagent Systems Under DoS Attacks.

Consensus control of multiagent systems (MASs) has applications in various domains. As MASs work in networked environments, their security control becomes critically desirable in response to various cyberattacks, such as denial of service (DoS). Efforts have been made in the development of both time- and event-triggered consensus control of MASs. However, there is a lack of precise calculation of control input during the attacking periods. To address this issue, a distributed secure consensus control with event triggering is developed for linear leader-following MASs under DoS attacks. It is designed with a dual-terminal event-triggered mechanism, which schedules information transmission through two triggered functions for each follower: one on the measurement channel (sensor-to-controller) and the other on the control channel (controller-to-actuator). To deal with DoS attacks, the combined states in the triggered functions are replaced by their estimations from an observer. Sufficient conditions are established for the duration and frequency of DoS attacks. To remove continuous monitoring of the measurement errors, a self-triggered secure control scheme is further developed, which combines the system states and other information at past triggered instants. Theoretical analysis shows that the followers in MASs under DoS attacks are able to track the leader and meanwhile the Zeno behavior is excluded. Case studies are conducted to demonstrate the effectiveness of our distributed secure consensus control of MASs.

Event-Triggered Adaptive Optimal Fast Terminal Sliding Mode Control Under Denial-of-Service Attacks

This article develops an event-based adaptive optimal fast terminal sliding mode control (AOFTSMC) under malicious denial-of-service (DoS) attacks. It is supposed that the transmitted measurement signals are ruined by attackers randomly. A key issue is how to design the controller parameters to keep the desirable performance of the closed-loop system under DoS attacks which are characterized by their frequencies and durations. To this end, the event-based AOFTSMC is proposed first to increase robustness against the attack and reduce the computational load. Then, an explicit effect of the duration and frequency of DoS attacks on the stability of the closed-loop systems under the presented controller is analyzed. Moreover, the scheduling of controller updating times is determined. This leads to derive the maximum bandwidth of the cyber layer which is required to guarantee the stability of the closed-loop system. Then, the designer can outline suitable controller parameters in different situations in the presence of uncertainties and DoS attacks. Finally, numerical simulation results illustrate the validation and effectiveness of the proposed methodology.

Switching system-based load frequency control for multi-area power system resilient to denial-of-service attacks

Load frequency control (LFC) scheme of modern power systems tends to employ open communication networks to transmit control/measurement signals, which makes the LFC scheme more vulnerable to cyber-attacks such as a denial-of-service (DoS) attack. The DoS attack prevents signal transmission and degrades the performance of or even results in instability in the LFC scheme. This paper proposes a switching system-based approach to the LFC scheme of a multi-area power system that is resilient to DoS attacks. After modelling the LFC scheme under DoS attacks as switching subsystems based on the duration of DoS attacks, a new stability criterion in terms of the duration and frequency of DoS attacks is developed. The derived criterion can be used to calculate the maximum duration and frequency of DoS attacks that the LFC system with a given proportional–integral (PI)-type controller can tolerate and to determine the control gains of the PI-type controller for a given duration and frequency of DoS attack. Moreover, a resilient LFC scheme is proposed based on a dual-loop communication channel equipped with the designed PI controller. The effectiveness of the proposed LFC scheme is evaluated on a traditional three-area power system and a deregulated three-area power system under DoS attacks.

RQ-CEASE: A Resilient Quantized Collaborative Event-Triggered Average-Consensus Sampled-Data Framework Under Denial of Service Attack

Referred to as the RQ-CEASE, this article proposes a resilient framework for quantized, event-triggered (ET), sampled-data, average consensus in multiagent systems subject to denial of service (DoS) attacks. The DoS attacks typically attempt to block the measurement and communication channels in the network. Two different ET approaches are considered in RQ-CEASE based on whether the ET threshold is dependent or independent of the state dynamics. For each approach, we analytically derive operating conditions (bounds) for the sampling period and ET design parameter guaranteeing the input-to-state stability (ISS) of the network under DoS attacks. In addition, upper bounds for duration and frequency of DoS attacks are derived within which the network remains operational. For each approach, the maximum possible error from the average consensus value is derived. The resilience of the two RQ-CEASE approaches to DoS attacks, as well as their steady-state consensus error, and transmission savings are compared both analytically and using simulations.

Stabilization of Networked Control Systems Under DoS Attacks and Output Quantization

This article addresses quantized output feedback stabilization under denial-of-service (DoS) attacks. First, assuming that the duration and frequency of DoS attacks are averagely bounded and that an initial bound of the plant state is known, we propose an output encoding scheme that achieves exponential convergence with finite data rates. Next, we show that a suitable state transformation allows us to remove the assumption on the DoS frequency. Finally, we discuss the derivation of state bounds under DoS attacks and obtain sufficient conditions on the bounds of DoS duration and frequency for achieving Lyapunov stability of the closed-loop system.