## 2 Related Works
In ETERS, the trust function is defined based on the \(\beta\) distribution. Moreover, this scheme has an irregular attenuation factor when evaluating communication trust. This factor shows the effect of various external elements, for example, earthquakes or network congestion. In ETERS, an attack detection algorithm called TADA analyzes the reliability of the nodes. It depends on three scales, namely ID, location, and the trust solution. Note that the trust solution applies a timing window with variable length to eliminate some constraints of existing trust mechanisms. ETERS designs a secure routing technique based on the proposed trust solution to form an energy-efficient connection between network nodes. The simulation results show that ETERS has a successful performance in terms of PDR, consumed energy, and latency. In [34], an RPL-based secure routing protocol called SPRL is offered. It focuses on the rank manipulation issue. For solving this issue, SPRL defines a novel concept called rank threshold and a hash chain-based authentication mechanism. The purpose of these techniques is to control the change rate of the rank value. Now, if the hostile nodes carry out internal attacks by changing the rank value, SPRL does not allow them to change their positions on the destination-oriented directed acyclic graph (DODAG) in the RPL network. To reduce the effect of the attack, this scheme defines a threshold function to check the rank value in RPL. SPRL protects RPL against the rank manipulation attack based on these threshold functions. In addition, an authentication concept is introduced in SPRL to provide better security. In the authentication process, each node earns a rank threshold. The simulation results show that SPRL can protect the RPL network, but this scheme is unsuitable for some attacks. In this scheme, thresholds are defined for all nodes, i.e., malicious or normal nodes. This causes additional overhead. In [35], a trust-aware routing scheme called SecTrust-RPL is introduced for IoT networks. It is suitable for protecting the IoT network against both rank and Sybil attacks. SecTrust-RPL is responsible for performing two operations, namely the attack detection and the malicious node isolation. In the first step, each IoT node obtains its trust with regard to the direct trust and the trust recommended by its neighbors. Neighboring IoT devices with a bigger trust value are chosen to execute the secure routing operation. In contrast, neighboring IoT devices that obtain a lower trust value are considered malicious nodes or selfish nodes. This method allows trusted nodes to form safe communication only with other trusted nodes. Moreover, trust information is shared with neighboring IoT nodes in the network. SecTrust-RPL validates the trust of each transmitter node to secure the data transmission path. The simulation results show that SecTrust-RPL resists rank attacks. However, it does not consider the uncertainty in the recommendations. In [36], an energy harvesting trust-aware routing approach (EHTARA) is provided to design a trust-based routing framework in IoT. EHTARA determines the most suitable route based on a cost parameter, which depends on factors such as energy, distance, and trust. The base station classifies big data using the deep belief network (DBN). In EHTARA, this network is trained based on the E-Bat algorithm, which integrates the exponential weighted moving average (EWMA) and the bat algorithm (BA). The purpose of this technique is to choose a node with the maximum remaining energy and the lowest link cost. This work is performed based on the shortest route technique. Furthermore, EHTARA specifies suitable paths for the data transmission process using energy harvesting parameters. It consumes energy efficiently. In [37], a trust-based secure routing approach called SMTrust is suggested in the Internet of Things. This scheme is suitable for IoT with constrained sources. SMTrust deals with rank and blackhole attacks because these negatively affect the routing process.