With the increasing diversity of Distributed Denial-of-Service (DDoS) attacks, it is becoming extremely challenging to design a fully protected network. For instance, Stealthy Link Flooding Attack (SLFA) is a variant of DDoS attacks that strives to block access to a target area by flooding a small set of links, and it is shown that it can bypass traditional DDoS defense mechanisms. One potential solution to tackle such SLFAs is to apply Moving Target Defense (MTD) techniques in which network settings are dynamically changed to confuse/deceive attackers, thus making it highly expensive to launch a successful attack. However, since MTD comes with some overhead to the network, to find the best strategy (i.e., when and/or to what extent) of applying it has been a major challenge. The strategy is significantly influenced by the attacker's behavior that is often difficult to guess. In this work, we address the challenge of obtaining the optimal MTD strategy that effectively mitigates SLFAs while incurs a minimal overhead. We design the problem as a signaling game considering the network defender and the attacker as players. A belief function is established throughout the engagement of the attacker and the defender during this SLFA campaign, which is utilized to pick the best response/action for each player. We analyze the game model and derive a defense mechanism based on the equilibria of the game. We evaluate the technique on a Mininet-based network environment where an attacker is performing SLFAs and a defender applies MTD based on equilibria of the game. The results show that our signaling game-based dynamic defense mechanism can provide a similar level of protection against SLFAs like the extensive MTD solution, however, causing a significantly reduced overhead.

The supervisory control and data acquisition (SCADA) network in a smart grid requires to be reliable and efficient to transmit real-time data to the controller, especially when the system is under contingencies or cyberattacks. Introducing the features of software-defined networks (SDN) into a SCADA network helps in better management of communication and deployment of novel grid control operations. Unfortunately, it is impossible to transform the overall smart grid network to have only SDN-enabled devices overnight because of budget and logistics constraints, which raises the requirement of a systematic deployment methodology. In this article, we present a framework, named SDNSynth, that can design a hybrid network consisting of both legacy forwarding devices and programmable SDN-enabled switches. The design satisfies the resiliency requirements of the SCADA network, which are determined with respect to a set of pre-identified threat vectors. The resiliency-aware SDN deployment plan primarily includes the best placements of the SDN-enabled switches (replacing the legacy switches). The plan may include one or more links to be installed newly to provide flexible or alternate routing paths. We design and implement the SDNSynth framework that includes the modeling of the SCADA topology, SDN-based resiliency measures, resiliency threats, mitigation requirements, the deployment budget, and other constraints. It uses satisfiability modulo theories (SMT) for encoding the synthesis model and solving it. We demonstrate SDNSynth on a case study of an example small-scale network. We also evaluate SDNSynth on different synthetic SCADA systems and analyze how different parameters impact each other. We simulate the SDNSynth suggested networks in a Mininet environment, which demonstrate the effectiveness of the deployment strategy over traditional networks and randomly deployed SDN switches in terms of packet loss and recovery time during network congestions.

The use of Unmanned Aerial Vehicles (UAVs) for collecting data from remotely located sensor systems is emerging. The data can be time-sensitive and require to be transmitted to a data processing center. However, planning the trajectory for a swarm of UAVs depends on multi-fold constraints, such as data collection requirements, UAV maneuvering capacities, and budget limitations. Since a UAV may fail or be compromised, it is important to provide necessary resilience to such contingencies, thus ensuring data security. It is important to provide the UAVs with efficient spatio-temporal trajectories so that they can efficiently cover necessary data sources. In this work, we present Synth4UAV, a formal approach for automated synthesis of efficient trajectories for a UAV swarm by logically modeling the aerial space and data point topology, UAV moves, and associated constraints in terms of the turning and climbing angle, fuel usage, data collection point coverage, data freshness, and resiliency properties. We use efficient, logical formulas to encode and solve the complex model. The solution to the model provides the routing and maneuvering plan for each UAV, including the time to visit the points on the paths and corresponding fuel usage such that the necessary data points are visited while satisfying the resiliency requirements. We evaluate the proposed trajectory synthesizer, and the results show that the relationship among different parameters follows the requirements while the tool scales well with the problem size.

In modern energy control centers, the Optimal Power Flow (OPF) routine is used to determine individual generator outputs that minimize the overall cost of generation while meeting transmission, generation, and system level operating constraints. OPF relies on the output of another module, namely the state estimator, which computes all the system variables, principally the voltage magnitudes with phase angles, transmission line flows, and the bus (and total system) loads. However, recent works have shown that the widely used weighted least square based state estimation is vulnerable to stealthy attacks wherein an adversary can alter certain measurements to corrupt the estimator's solution, yet remain undetected by the estimator's bad data detection algorithm. Here, we show that an attack on state estimation can compromise the integrity of OPF and undermine the economic and secure system operation. We present a formal verification based framework to systematically investigate the feasibility of such stealthy attacks and their influence on OPF. The proposed approach is described with an illustrative example. We also develop a mechanism to increase the efficiency of executing our model, which is evaluated by running experiments on different IEEE test cases.

Background: Using remote monitoring technology in the context of Alzheimer disease (AD) care presents exciting new opportunities to lessen caregiver stress and improve patient care quality. The application of wearables, environmental sensors, and smart home systems designed specifically for patients with AD represents a promising interdisciplinary approach that integrates advanced technology with health care to enhance patient safety, monitor health parameters in real time, and provide comprehensive support to caregivers. Objective: The objectives of this study included evaluating the effectiveness of various remote sensing technologies in enhancing patient outcomes and identifying strategies to alleviate the burden on health care professionals and caregivers. Critical elements such as regulatory compliance, user-centered design, privacy and security considerations, and the overall efficacy of relevant technologies were comprehensively examined. Ultimately, this study aimed to propose a comprehensive remote monitoring framework tailored to the needs of patients with AD and related dementias. Methods: Guided by the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) framework, we conducted a systematic review on remote monitoring for patients with AD and related dementias. Our search spanned 4 major electronic databases—Google Scholar, PubMed, IEEE Xplore, and DBLP on February 20, 2024, with an updated search on May 18, 2024. Results: A total of 31 publications met the inclusion criteria, highlighting 4 key research areas: existing remote monitoring technologies, balancing practicality and empathy, security and privacy in monitoring, and technology design for AD care. The studies revealed a strong focus on various remote monitoring methods for capturing behavioral, physiological, and environmental data yet showed a gap in evaluating these methods for patient and caregiver needs, privacy, and usability. The findings also indicated that many studies lacked robust reference standards and did not consistently apply critical appraisal criteria, underlining the need for comprehensive frameworks that better integrate these essential considerations. Conclusions: This comprehensive literature review of remote monitoring technologies for patients with AD provides an understanding of remote monitoring technologies, trends, and gaps in the current research and the significance of novel strategies for remote monitoring to enhance patient outcomes and reduce the burden among health professionals and caregivers. The proposed remote monitoring framework aims to inspire the development of new interdisciplinary research models that advance care for patients with AD.

Intelligent false data injection on load measurements can trigger false relay operation (FRO) of frequency-based protection relays, affecting the power system frequency and thus threatening the security of power systems. In this paper, we propose an optimization-based formal model to find the optimal false data injection attack (OFDIA) with the minimum required time leading to an FRO. The proposed model considers the dynamic behavior of the power system in an optimization framework to find the optimal size of attacks over multiple generators’ dispatching cycles to minimize the attack launch time. Using the proposed formal modeling, we study the impact of power system parameters, including inertia, governor’s droop and time constant, and the attacker’s accessibility to loads on the attack success and launch time. The results demonstrate that systems with low inertia are more vulnerable to FDIAs while systems with higher inertia are more secure as fewer generator protection relays are impacted by FRO. In addition, we show that securing more load meters can increase the time for launching an attack in the system. Moreover, our studies show that a combination of large values of the governor’s time constants and small values of the governor’s droops can raise the time of successful attacks, making the system more secure against FDIAs.