Contents I. Introduction
Internet of Things (IoT) has become a domain of immense influence that offers novel services to various applications [1]. An IoT Smart Irrigation System (ISIS) is a prominent IoT application that controls water use precisely according to cultures' water demands. It depends on numerous climatic and soil parameters such as air temperature, humidity, and soil moisture where plants grow [2]. However, the current architucture of ISIS as illustrated in Fig. 1 is highly susceptible to cyberattacks at Cloud, Fog and Edge layers. Therefore, integrity, tractability, and authentication mechanisms are required to detect security issues and deny unauthorized interactions with the system. Using the BC security framework in the IoT makes a lot of sense since it offers immutability, trust, and anonymity. However, the challenging problem which will be taken is how to adapt the BC technology to low-cost equipment included in smart irrigation system, such as microcontrollers and cheap computers. The main objective of our work is to improve our previous work [3], [4] by including the security aspect in ISIS. To achieve this goal, we implemented a lightweight Proof of Authority (PoA) consensus similar to Aura (Authority Round) [6]. This mechanism is designed to overcome the security limitations reported in private BCs by taking into account the reputation of validator nodes. Finally, we apply our solution to the existing ISIS prototype. The rest of the paper is organized as follows: Section II briefly surveys the related work. Section III presents the security of ISIS based on BC technology. Section IV describes the ISIS prototype's implementation aspects and hardware components. Section V presents the performance evaluation of our solution and discusses the experimental results. Section VI concludes the paper and outlines the directions for future work.
