Self-triggered coordination over a shared network under Denial-of-Service

Abstract

Abstract-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. I. INTRODUCTIONIn recent years, the issue of security has become ever more prevalent in the analysis and design of cyber-physical systems (CPSs), namely systems that exhibit a tight conjoining of computational resources and physical resources. As argued in [1], [2], security in CPSs drastically differs from security in general-purpose computing systems since attacks can cause disruptions that transcend the cyber realm and affect the physical world. In CPSs, attacks to the communication links can be classified as either deception attacks or Denial-ofService (DoS) attacks. The former affect the trustworthiness of data by manipulating the packets transmitted over the network; see [3]-[5] and the references therein. DoS attacks are instead primarily intended to affect the timeliness of the information exchange, i.e., to cause packet losses; see for instance [6], [7] for an introduction to the topic. This paper is concerned with DoS attacks.In the literature, the problem of securing robustness of CPSs against DoS has been investigated by many research groups [8]- [13]. In these papers, however, the analysis is restricted to a centralized setting, namely to a classical (single-loop) plantcontroller configuration. On the other hand, no quantitative results are available for distributed settings. The purpose of this paper is to explore this topic.We investigate the issues of DoS with respect to consensus networks. Specifically, inspired by [14], we consider a self-triggered consensus network. At each sampling time, a certain subset of active agents poll their neighbors obtaining relative measurements of the consensus variable of interest: the available information is then used by the active agents to update their controls and compute their next update times. The attacker objective is to prevent consensus by denying communication among the agents. Consensus is a prototypical problem in distributed settings with a huge range of applications, spanning from formation and cooperative robotics to

Networked Systems under Denial-of-Service: Co-located vs. Remote Control Architectures

“…The contribution is an explicit characterization of DoS frequency and duration for which stability can be preserved through state-feedback control. Extensions have been considered dealing with co-located robust controller design (Feng and Tesi, 2017), nonlinear (De Persis and Tesi, 2014a) and distributed (Senejohnny et al, 2015) systems, as well as with systems where jamming attacks and genuine packet losses coexist (Cetinkaya et al, 2016).…”

A New Cyber-Secure Countermeasure for LTI systems under DoS attacks

“…Given the system dynamics (17), we consider the control law u(t) = K x(t), where K ∈ R 10×20 is the feedback gain matrix. The gain matrix K is designed based on the sparsity promoting algorithm (10). First, we start minimizing (10) for a small initial value of β.…”

“…We initialize a small value of β ∈ R denoted as β initial . It results a centralized LQR gain K = K c ∈ R m×n , and starts minimizing (10). As stated earlier, the solution of (10) becomes sparser as β increases; hence we obtain different footprints of the sparsity pattern of K by varying β.…”

“…Given a LTI system, [8] presents a novel analysis methodology to maintain the closed loop stability under DoS attacks, while [9] unveils a similar analysis for its nonlinear counterpart. Given a class of complex networks, [10] analyzes the consensus property of self-triggered agents in the presence of DoS attacks. The analysis documented in [10] introduces the notion of persistence-of-communication and characterizes DoS frequency and duration to attain consensus under DoS attacks.…”

“…Given a class of complex networks, [10] analyzes the consensus property of self-triggered agents in the presence of DoS attacks. The analysis documented in [10] introduces the notion of persistence-of-communication and characterizes DoS frequency and duration to attain consensus under DoS attacks.…”