Biblio

With the remarkable growth of the Internet and communication technologies over the past few decades, Internet of Things (IoTs) is enabling the ubiquitous connectivity of heterogeneous physical devices with software, sensors, and actuators. IoT networks are naturally two layers with the cloud and cellular networks coexisting with the underlaid device-to-device communications. The connectivity of IoTs plays an important role in information dissemination for mission-critical and civilian applications. However, IoT communication networks are vulnerable to cyber attacks including the denial-of-service and jamming attacks, resulting in link removals in the IoT network. In this paper, we develop a heterogeneous IoT network design framework in which a network designer can add links to provide additional communication paths between two nodes or secure links against attacks by investing resources. By anticipating the strategic cyber attacks, we characterize the optimal design of the secure IoT network by first providing a lower bound on the number of links a secure network requires for a given budget of protected links, and then developing a method to construct networks that satisfy the heterogeneous network design specifications. Therefore, each layer of the designed heterogeneous IoT network is resistant to a predefined level of malicious attacks with minimum resources. Finally, we provide case studies on the Internet of Battlefield Things to corroborate and illustrate our obtained results.

Designing secure systems is a complex task, particularly for designers who are no security experts. Cyber security plays a key role in embedded systems, especially for the domain of the Internet of Things (IoT). IoT systems of this kind are becoming increasingly important in daily life as they simplify various tasks. They are usually small, either embedded into bigger systems or battery driven, and perform monitoring or one shot tasks. Thus, they are subject to manifold constraints in terms of performance, power consumption, chip area, etc. As they are continuously connected to the internet and utilize our private data to perform their tasks, they are interesting for potential attackers. Cyber security thus plays an important role for the design of an IoT system. As the usage of security measures usually increases both computation time, as well as power consumption, a conflict between these constraints must be solved. For the designers of such systems, balancing these constraints constitutes a highly complex task. In this paper we propose a novel approach for considering possible security attacks on embedded systems, simplifying the consideration of security requirements immediately at the start of the design process. We introduce a security aware design space exploration framework which based on an architectural, behavioral and security attack description, finds the optimal design for IoT systems. We also demonstrate the feasibility and the benefits of our framework based on a door access system use case.

In this paper, we consider the problem of designing system parameters to improve detection of attacks in control systems. Specifically, we study control systems which are vulnerable to integrity attacks on sensors and actuators. We aim to defend against strong model aware adversaries that can read and modify all sensors and actuators. Previous work has proposed a moving target defense for detecting integrity attacks on control systems. Here, an authenticating subsystem with time-varying dynamics coupled to the original plant is introduced. Due to this coupling, an attack on the original system will affect the authenticating subsystem and in turn be revealed by a set of sensors measuring the extended plant. Moreover, the time-varying dynamics of the extended plant act as a moving target, preventing an adversary from developing an effective adaptive attack strategy. Previous work has failed to consider the design of the time-varying system matrices and as such provides little in terms of guidelines for implementation in real systems. This paper proposes two optimization problems for designing these matrices. The first designs the auxiliary actuators to maximize detection performance while the second designs the coupling matrices to maximize system estimation performance. Numerical examples are presented that validate our approach.