A Jamming-Resilient Algorithm for Self-Triggered Network Coordination

The issue of cyber-security has become ever more prevalent in the analysis and design of cyber-physical systems. In this paper, we investigate self-triggered consensus networks in the presence of communication failures caused by denial-of-service (DoS) attacks. A general framework is considered in which the network links can fail independent of each other. By introducing a notion of persistency-of-communication (PoC), we provide an explicit characterization of DoS frequency and duration under which consensus can be preserved by suitably designing time-varying control and communication policies. An explicit characterization of the effects of DoS on the consensus time is also provided. The considered notion of PoC is compared with classic average connectivity conditions that are found in pure continuous-time consensus networks. Finally, examples are given to substantiate the analysis

Self-triggered Coordination over a Shared Network under Denial-of-Service

The issue of security has become ever more prevalent in the analysis and design of cyber-physical systems. In this paper, we analyze a consensus network in the presence of Denial-of-Service (DoS) attacks, namely attacks that prevent communication among the network agents. By introducing a notion of Persistency-of-Communication (PoC), we provide a characterization of DoS frequency and duration such that consensus is not destroyed. An example is given to substantiate the analysis

Resilient Control Under Denial-of-Service:Results and Research Directions

The question of security is becoming central for the current generation of engineering systems which more and more rely on networks to support monitoring and control tasks. This chapter addresses the question of designing network control systems that are resilient to Denial-of-Service, that is to phenomena which render a communication network unavailable to use. We review recent results in this area and discuss some of the research challenges.</p

Cyber-Resilient Self-Triggered Distributed Control of Networked Microgrids Against Multi-Layer DoS Attacks

Networked microgrids with high penetration of distributed generators have ubiquitous remote information exchange, which may be exposed to various cyber security threats. This paper, for the first time, addresses a consensus problem in terms of frequency synchronisation in networked microgrids subject to multi-layer denial of service (DoS) attacks, which could simultaneously affect communication, measurement and control actuation channels. A unified notion of Persistency-of-Data-Flow (PoDF) is proposed to characterise the data unavailability in different information network links, and further quantifies the multi-layer DoS effects on the hierarchical system. With PoDF, we provide a sufficient condition of the DoS attacks under which the consensus can be preserved with the proposed edgebased self-triggered distributed control framework. In addition, to mitigate the conservativeness of offline design against the worst-case attack across all agents, an online self-adaptive scheme of the control parameters is developed to fully utilise the latest available information of all data transmission channels. Finally, the effectiveness of the proposed cyber-resilient self-triggered distributed control is verified by representative case studies

Resilience of coordination networks: data availability and integrity

With the advent of new concepts like Internet of Things (IoT), Industrial 4.0, Smart Cities, Smart Grid, new opportunities are brought into several industrial and societal domains ranging from transportation and electric power generation to traffic flow management and health care. Many of the above mentioned sectors and industries are essential to the health, safety, and security of our society and are considered critical infrastructure. This emphasizes the importance of rendering such systems “resilient” against malfunctioning due to genuine failures or cyberattacks. Real-time availability and integrity of data are crucial to ensure normal operation of the system. The first factor is related to to the fact that data flow can be occasionally interrupted, while the second factor is related to the fact that the data content might be corrupted. Given these important factors, this thesis investigates the problem of designing coordination protocols over digital communication channels, which are resilient against the lack of data and unreliable information. The results are divided in two parts. Part I is concerned with resilience against the absence of data and information accessibility due to genuine failure or cyberattacks, which results in Denial-of-Service (DoS). In particular, we are concerned with jamming attacks as we are mainly interested in wireless sensor networks. We design resilient consensus and synchronization protocols for both shared and peer-to-peer communication networks. Part II is concerned with resilience against unreliable information in the network which could be the result of genuine fault/error in the control system operation or cyberattack. The nodes that communicate untrustworthy data in the network are considered misbehaving. We investigate a resilient consensus protocol against several type of misbehavior resulting from error in operations such as, data acquisition, data transmission, control logic, and update time scheduler