Event-triggered [formula omitted] consensus for nonlinear multi-agent systems with semi-Markov switching topologies under DoS attacks

This article examines the nonfragile bipartite tracking consensus issue in the context of sampled-data nonlinear multiagent systems (MASs) undergoing denial-of-service (DoS) attacks and control gain fluctuations, where both cooperative and competitive interactions between the agents over the network are taken into account. During the DoS attacks, with communication services being denied, a halt in data transmission among the agents is experienced, which might result in performance degradation, undesirable oscillatory behavior, or even hinders the agents from performing their intended tasks. Consequently, there emerges a pressing requirement for the analysis and design of a secure bipartite tracking consensus protocol for MASs under the threat of DoS attacks. In pursuit of this goal, a modified Halanay-like inequality is initially established, which provides a basis for us to derive certain sufficient conditions ensuring the MASs to achieve the bipartite tracking consensus, despite the disruptive presence of malicious DoS attacks. Additionally, the control gain matrix can be readily computed by resolving a collection of linear matrix inequalities. For specific scenarios that demand reduced computational complexity, the matrix decoupling method is introduced, enabling a reduction in the dimensionality of the matrix inequalities and, consequently, facilitating its straightforward application to large-scale MASs. This article culminates in a numerical simulation, which is performed to validate the developed results.

Secure consensus for PDEs-based multiagent systems under DoS attacks via boundary control approach

This chapter focuses on the very serious problem of denial of service (DoS) attacks against computer systems and networks. DoS attacks are attacks designed to disrupt, overwhelm, and/or damage computing resources and data. These attacks are aimed not against confidentiality of data or integrity of systems and data, but rather against availability of systems and data. Attackers launch DoS attacks for a wide variety of reasons. The probability of success is high, due in large part to the fact that the Internet itself has not been designed for security. The cost of DoS attacks is often high—several well‐known attacks have reportedly cost organizations billions of dollars. Many types of DoS attacks have surfaced so far, including resource starvation attacks, buffer overflow attacks, and packet fragmentation attacks. Distributed denial of service (DDoS) attacks, attacks in which programs planted in multiple systems cooperate, represent an even higher level of threat. Preventing DoS attacks is difficult in the first place due to a plethora of reasons; limiting the potential for damage and disruption is often the most cost‐effective strategy. Hot sites, cold sites, use of uninterruptible power supplies (UPSs) and Redundant Array of Independent Drives (RAID) solutions, and other measures can limit the damage from DoS attacks. Using properly configured and maintained firewalls is one of the best single prevention measures. Additionally, using packet filters on systems, keeping up with patches, limiting services that run on these systems, and using other measures go a long way in helping prevent susceptibility to DoS attacks.

Fixed-time leader-following/containment consensus of nonlinear multi-agent systems based on event-triggered mechanism

This paper investigates the event-triggered prescribed-time bipartite consensus of nonlinear multi-agent systems. In order to significantly reduce the communication burden and energy consumption, a novel event-triggered mechanism and triggering condition are proposed. Then, a distributed prescribed-time control protocol is proposed for the discussed nonlinear multi-agent systems to achieve bipartite consensus within the prescribed time based on the event-triggered mechanism. Using the Lyapunov stability theory, the stability of the nonlinear multi-agent systems is proved and the corresponding sufficient conditions are obtained. Moreover, it is shown that the Zeno behavior can be excluded. Simulation results are presented to show the effectiveness of the theoretical results.

In WSN, DoS (denial of service) attack makes shortcoming system. The packets travel over and over in the sensor network. By that, all the assets like data transmission, memory, and vitality are squandered by this attack. However, the attacker ought to optimize its attacker plan for request to boost the impact on the system performance because of the deficiency of vitality at the aggressor side. Denial of service (DoS) attack on the Internet has become a squeezing issue. By staying away from these sorts of attacks, network performance can be improved. Therefore, security is a fundamental requirement for these networks. Effective routing is necessary in order to overcome the issued faced by the crosslayer in the DOS attack of the WSN network for the purpose of good transmission. This research work mainly focuses on performance evaluation using optimization methods. To establish the efficient path in the crosslayer against DoS attack, this paper has proposed enhanced lion optimization with an efficient path routing equalization technique (LOEPRE). If any failure node occurs in the network, then the node is recognized and the transfer of the data packet is done to the other node. Retransmission of data causes overload in the network. The proposed model focuses on these issues and overcomes these issues by improving the path efficiently with robust security. It consists of three phases: the initial phase includes the route discovery in the network. In the second phase, the transfer of data is done in the high router path for security purposes. Finally, the efficient path routing equalization technique is used for minimizing the overload in the network; it provides the equalized path length in the network and is highly efficient. Hence, the proposed LOEPRE technique is used to achieve energy efficiency in wireless network for prolonged network lifetime and minimum packet latency and minimize consumption of energy. Moreover, the simulation outcome of the proposed LOEPRE method is highly robust while comparing to the existing methods EFCRS, SSPRA ELOER, EFLOR, and TSTP. It achieves better performance than existing algorithms in comparing metric connectivity ratio, end-to-end delay, overhead, throughput, and packet delivery ratio.

Wireless network security has received tremendous attention due to the vulnerabilities exposed in the open communication medium. The most common wireless Medium Access Control (MAC) protocol is IEEE 802.11, which assumes all the nodes in the network are cooperative. However, nodes may purposefully misbehave in order to disrupt network performance, obtain extra bandwidth and conserve resources. These MAC layer misbehaviours can lead to Denial of Service (DoS) attacks which can disrupt the network operation. There is a lack of comprehensive analysis of MAC layer misbehaviour driven DoS attacks for the IEEE 802.11 protocol in MANETs. This research studied possible MAC layer DoS attack strategies that are driven by the MAC layer malicious/selfish nodes on IEEE 802.11 protocol. Such DoS attacks could caused by malicious and selfish nodes by violating their backoff timers associated with the MAC protocol. Therefore, these attacks are experimentally analysed and evaluated the impact on the network performance and stability in MANETs. The simulation results show that introducing DoS attacks at MAC layer could significantly affect the network throughput and data packet collision rate. This paper concludes that DoS attacks with selfish/malicious intend can obtain at least 50% larger throughput by denying well-behaved nodes to obtain deserved throughput, also DoS attacks with the intend of complete destruction which allow only less than 5% throughput for well-behaved nodes which eventually led to shut-down of the network.

This article investigates the leader-following consensus problem of discrete-time nonlinear multiagent systems (MASs) over fading channels. With the consideration of the transmission among followers maybe affected by the fading networks, the nonidentical fading channels model is constructed. To reduce the transmission network burden, the dynamical event-triggered mechanism (DETM) is developed. Different from most of existing event-triggered strategies, the threshold parameter in the developed dynamical event-triggering condition is dynamically adjusted according to a dynamic rule. Based on the DETM, a distributed consensus control protocol is designed under fading channels. Then, sufficient criteria are provided to ensure that MASs can achieve the leaser-following consensus, and satisfy the H∞ performance index in the presence of fading channels. The desired controller parameters can be derived in terms of solutions of matrix inequalities that are lightly solvable. In the end, simulation results show that the designed dynamical event transmission policy is capable of diminishing communication burden more promptly and effectively than some existing ones.

To measure the degree of basic service of wireless sensor network (WSN) with denial of service (DoS) attacks, it is necessary to evaluate survivability of WSN. This paper presents new method based on services and Markov Chain. It distinguishes services, analyzes influence of services under DoS attacks, gets the formula of survivability. Probability of states is obtained by markov chain, then the quantitve survivability is getted in different states. Simulations prove that DoS attacks obviously decrease the survivability of WSN, but adding node energy and improving node density in certain range can reduce the influence of DoS attacks.

Denial of Service (DoS) or Distributed Denial of Service (DDoS) is a powerful attack which prevents the system from providing services to its legitimate users. Several approaches exist to filter network-level attacks, but application-level attacks are harder to detect at the firewall. Filtering at application level can be computationally expensive and difficult to scale, while still creating bogus positives that block legitimate users. In this paper, authors show application layer DoS attack for SIP server using some open source DoS attack tools and also suggest a mechanism that can protect a given SIP server from application-level DoS attacks especially the attacks targeting the resources including CPU, sockets, memory of the victim server. In this paper author’s attempt to illustrate application layer distributed denial of Service (DDoS) attack on SIP Server such as SIP flooding attack, real time transport (RTP) flooding attack using open source DDoS attack tools. We propose a new DDoS defence mechanism that protects SIP servers from application-level DDoS attacks based on the two methodologies: IPtables and fail2ban detection. The attack flow detection mechanism detects attach flows based on the symptom or stress at the server, since it is getting more difficult to identify bad flows only based on the incoming traffic patterns. A popular software known as Wireshark which is a network protocol analyzer is used to capture the packets during DoS attack from the victim server Ethernet interface to detect the attacking host IP address and analysis the types of attack. We evaluate the performance of the proposed scheme via experiment

In ad-hoc and wireless networks, Denial of Service (DoS) attacks has always been problematic during data routing. DoS attacks disrupt the data routing and avert the generated data to reach the destination or the sink nodes. In tunnel attack, which is one of the type of DoS attacks, the intruder attracts all the traffic towards itself and prevent it from forwarding further to the neighboring nodes. Researchers have presented multiple solutions to cater the problem and minimize or avoid the tunnel attacks, but they all have their shortcomings. The main reason behind all the drawbacks is that those solutions have not been confirmed using formal methods. The formal methods can be utilized to authenticate whether or not the solutions are immune to DoS attacks. In our previous researches, it has been revealed that by employing formal methods, our newly developed protocol RAEED can detect and avoid many DoS attacks. In this research paper, it has been proved using model checker that RAEED can efficiently avoid both simple and intelligent tunnel attacks. Moreover, the results of formal methods have been confirmed with the help of computer simulations as well as practical implementation on MicaZ motes. In future we aim to employ formal methods to verify more wireless communication issues in multiple protocols.

Event-based leader–follower consensus of nonlinear multi-agent systems under denial-of-service

Current management for charging stations with power coupling items and three charging modes of electric vehicles under DoS attacks

The performance of multi‐agent systems can be severely impacted by malicious attacks, particularly denial of service (DoS) attacks. These attacks can block communication channels, disrupt inter‐agent communication, and potentially lead to system paralysis. Furthermore, most practical systems are nonlinear, making the design of observers and controllers for such systems especially important. This paper addresses the challenge of leader‐follower consensus in One‐Sided Lipschitz (OSL) nonlinear systems under DoS attacks. We propose the design of an Unknown Input Observer (UIO) for nonlinear systems exhibiting both OSL and Quadratically Inner‐Bounded (QIB) characteristics, enabling unknown input reconstruction (UIR) and asymptotic state estimation. The key advantage of the proposed UIO is its reliance solely on output information, which makes it inherently resilient to DoS attacks during UIR and state estimation. To further enhance resilience, buffer units are introduced to store real‐time data, allowing the system to retrieve the most recent state information during an attack and maintain continuous communication. Under simultaneous DoS attacks, OSL nonlinearity, and unknown inputs, we propose a control protocol that guarantees leader‐follower consensus. Additionally, we derive upper bounds on the frequency and duration of DoS attacks that allow consensus to be maintained. Numerical simulations validate the effectiveness and robustness of the proposed approach.

Cloud Network has emerged as one of the most adopted technologies both among the end-users and the developers. Despite cloud networks being popular, security in cloud remains a pivotal research challenge and a topic that is much discussed about. Denial of service (DoS) attack is carried out in cloud by one or more perpetrators using multiple compromised nodes to flood a specific target and thereby resulting in unavailability of services. Classification methods can be used effectively to identify attack signature or recurring patterns of such DoS attacks. Therefore, classification using machine learning techniques have been used in this work for feature selection and classification in order to identify the DoS attacks. For this purpose, a new rule based approach for detecting the DoS attacks which uses a domain expert’s knowledge has been proposed in this paper. Moreover, two new algorithms namely Feature Selection Algorithm using Scoring and Ranking and Rule based Classification Algorithm for detecting DoS Attacks are proposed in this paper in which the final classification is carried out by applying the rules from the rule base and is validated using a domain-expert. We have evaluated the proposed system on an experimental set-up on cloud and used real time DoS tools and observed that the proposed method achieved better DoS attack detection accuracy than the existing classification algorithms used for security.