# Trust-Aware Fog-Based IoT Environments: Artificial Reasoning Approach
## 1 Introduction  
The Internet of Things (IoT) system is a new ever-growing communication technology in which various nodes such as sensors, smartphones, and devices communicate with one another through the internet [1, 2, 3, 4]. IoT environments' continuous growth and advancement have led to a higher level of availability, scalability, accessibility, and interoperability [1, 5]. However, these systems are vulnerable to cyberattacks, and hence the number of attacks is exponentially increasing due to various IoT devices and protocols, various attack surfaces, and a lack of security and trust standardizations and requirements [6, 7]. The rapidly growing concerns for security and trustworthiness of IoT-based systems/services have paved the way for researchers and practitioners to build trusted IoT environments [8, 9, 10, 11, 12]. Cyber intelligence research groups [13, 14, 15] have likewise pointed towards artificial intelligence as having a vital role in improving trust modeling and consequently focusing on IoT cybersecurity, including artificial intelligence schemes, usually in terms of modelling unusual behavior. When a separate entity holds each opinion, combining several opinions into a single opinion is a common task for artificial reasoning systems. Subjective logic, a framework for artificial reasoning [16, 17], is applicable when the situation to be analyzed is characterized by considerable epistemic vagueness resulting from incomplete knowledge. One of the prerequisites to providing appropriate IoT service levels is the need to consider the level of certainty and knowledge related to received information and the level of trust we have in the information source. Maintaining and updating a trust parameter specifically for the information source is one technique to ensure that [18; 19]. Increasing the amount of total work completed through the collection of resources is one of the goals of resource sharing [20; 21]. Sharing resources in a hostile environment necessitates strict security precautions to safeguard customers and the resources [22]. The costs associated with security provisioning may outweigh the performance benefits that resource sharing is intended to achieve. The sharing relationships can be limited to mutually trusting entities if the predicted trust levels between the various entities are known; as a result, the overhead associated with security provisioning can be decreased. IoT systems provide customers the right to access resources or services that would not otherwise be accessible to them [23; 24]. However, the risk involved in the concept of sharing resources or services makes the idea of having a virtual network structure unattractive [25]. Such clients choose to utilize their own closed box due to the vitality and sensitivity of the data or information. This kind of resource management is not only expensive but also ineffective. Clients and resources perceive such an environment as providing both possibilities and risks [24; 26]. Security threats, privacy concerns, and susceptibility to harm from malicious attacks are factors that impact people's trust in entities [3; 24; 26]. Malicious nodes are not trustworthy as defined in [3]. A node is trustworthy if there is a firm belief in the competence of the device to act as expected such that this firm belief is not a fixed value associated with the device but rather it is subject to the device's behavior and applies only within a specific context at a given time [3]. Trustworthiness-establishing techniques must be developed in this world of risk and uncertainty. In order to help entities determine how much trust to place in others, such techniques should be used. As a result, it is crucial to create trustworthy IoT settings [4; 9; 11]. Building trustworthy IoT environments also reduces irreparable and unforeseen losses, developing dependable, effective, and steady service-driven IoT systems. We cannot assume that every node in widely distributed networks is aware of every other node or that every node is reliable.