###### Abstract  
Wireless Sensor Networks (WSNs) are the core of the Internet of Things (IoT) technology, as they will be used in various applications in the near future. The issue of security and power consumption is still one of the most important challenges facing this type of network. 6 LoWPAN protocol was developed to meet these challenges in networks with limited power and resources. The 6 LoWPAN uses a hierarchical topology and the traditional method of encryption and key management, keeping power consumption levels high. Therefore, in this paper, a technique has been developed that helps in balancing security and energy consumption by exploiting the Trust technique between low-cost WSN nodes called Trust-Cluster Head (Trust-CH). Trust between nodes is built by monitoring the behavior of packet transmission, the number of repetitions and the level of security. The Trust-CH model provides a dynamic multi-level encryption system that depends on the level of Trust between WSN nodes. It also proposes a dynamic clustering system based on the absolute-trust level in the mobile node environment to minimize power consumption. Along with a set of performance metrics (i.e., power consumption and network lifetime), the Cooja simulator was used to evaluate the Trust-CH model. The results were compared to a static symmetric encryption model together with various models from previous studies. It has been proven that the proposed model increases the network lifetime by 40% compared to previous studies, as well as saves as much as 28% power consumption in the case of using a static encryption model. While maintaining the proposed model's resistance to many malicious attacks on the network. wireless sensor networks; trust management; dynamic clustering; WSN security; WSN life-time; low-cost sensors Article  
Adaptive Trust-Based Framework for Securing and Reducing Cost in Low-Cost 6 LoWPAN Wireless Sensor Networks April 2022128605  
IPv6, as in 6 LoWPAN. It is also related to the topological type, where the ZigBee uses the mesh and the other uses the hierarchical. Moreover, the 6 LoWPAN uses Low power and Lossy Networks (RPL) in the process of routing data to and from the AP and plots the topology. Both use standard Advanced Encryption Standard (AES) encryption [8]. Whereas, although AES is subject to a global standard, it is considered unsuitable for this type of network and its embedded devices [9]. It consumes more energy and power in encrypting and decrypting. The development and improved performance of these networks and sensors at present have an impact on the prices of these sensors. Inexpensive cost sensors are used in the majority of applications, including monitoring, humidity, rain, air, temperature, pedestrian monitoring, lighting, etc., due to their low cost and functional capabilities [10]. Therefore, several authors suggested modern encryption algorithms that are robust and reliable with lightweight in implementation, such as Speck128 [11], SIMON [11], Tiny Encryption Algorithm (TEA) [12] and FlexenTech [13]. Some of these lightweight encryption algorithms were analyzed in [14] to show that AES requires a high rate of power consumption. Furthermore, other works have proposed lightweight authentication algorithms for WSN [15] and others have used watermarking technology for the authentication process also [16] to reduce security costs and extend the WSN lifetime. Hence, due to the increasing demand for this type of device (low-cost WSN node) included in future applications, it requires these devices to run for longer periods. It also requires the provision of minimal data protection at the stage of data collection or the stage of its transmission (data) to other WSN nodes until it reaches the AP. Therefore, given the importance of these two parts (power consumption and security) for WSN nodes, some mechanisms contribute to their improvement in parallel.