## 2 Background Preliminaries
### CioT Systems and Miot Environments  
This study uses CioT as an umbrella term to define IoT environments that support mission-critical infrastructures or systems for mere civilian use and non-combative military use, such as smart transportation, the energy grid, and manufacturing plants. An industrial Internet of Things (IioT) is an example of a CioT. Notably, sixteen defined critical infrastructure sectors in the US span various domains, including industrial base defense [13]. In a CioT system, the various nodes are non-combative things operating in a non-combative mode to support combative and non-combative missions and operations, mainly in non-hostile environments.  
On the contrary, nodes in an Miot environment are mainly deployed in a combative mode to directly support combative operations, both logistic and tactical, in hostile environments. Miot environments generally consist of a mission-critical battlefield infrastructure for combative military operations. The Internet of the Battle Things, or IoBT, is an example of such an environment. The IoBT is a constellation of intelligent and marginally intelligent devices and equipment used in the battlefield [14]. CioT and Miot offer many benefits to support civilian and military tasks and critical operations. For example, a CioT system enables predictive analytics in operation, pricing, distribution, management, and maintenance, to list a few. In contrast, an Miot environment enables predictive battlefield analytics [15].  
CioT involves an integrated network of homogeneous and heterogeneous sensors and smart devices connected using edge and cloud infrastructures to support non-combative mission-critical tasks and operations. However, Miot involves a network of homogeneous and heterogeneous battlefield devices, intelligent and marginally intelligent, and wearable devices that are connected to support combative and battlefield operations. In an Miot environment, fog, edge, and cloud computing connect the ubiquitous sensors and IoT devices worn by military personnel and embedded in military equipment to create a cohesive fighting force to increase the situational awareness, risk assessment, and response time [14; 15; 16]. However, MioT uses mobile edge computing where IoT end devices transmit the data via a mobile edge server to a mobile base station [17].  
While a CioT tends to be stable and predictable with controlled or semi-controlled actions and reactions, an MioT is highly dynamic and unpredictable with rapid and controlled actions and reactions. The dynamic and unpredictable nature of an MioT environment dictates the need to dynamically learn and update the characteristics of the environment in real time. Figure 1 shows the connection of various sensor-based IoT devices in an MioT environment of an IoBT in contrast to a CioT environment of an IioT, as shown in Figure 2.  
Due to their critical mission, IoT nodes in CioT and MioT are more susceptible to targeted cyber attacks at a high rate compared to IoT nodes deployed in a normal IoT environment. In addition, MioT environments marry things and humans, whereas the battlefield things and connected soldiers sense, communicate, negotiate, and collaborate to coordinate offensive and defensive tasks and operations. However, in both environments, a compromised sensor-based node, e.g., operating at the perception or sensing layer, can have a deadly or catastrophic impact.