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