# Trust and Mobility-Based Protocol for Secure Routing in Internet of Things
## 3 Related Work
### Trust-Based Security Solutions
Moreover, critical security attacks, particularly routing attacks in RPL, are not evaluated in some trust-based network security solutions. Table 2 shows the highlights of the most related works for this study, including the shortcomings of the existing trust-based solutions. Hence, it can be figured out that the existing trust-based approaches for RPL security are not adequate from the perspective of the mobile IoT environment. \begin{table}
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**Ref.** & **Domain** & **Solution Technique** & **Evaluation Model** & **Mobility** & **Trust Metrics** & **Attacks Considered** & **Research Gaps/Improvements** \\ \hline \hline
[26] & RPL attacks/ IDS-based & ETX for calculating trust for routing topology. & Simulation— Contiki2.7/Cooja & ✗ & Energy; Honesty; Selfishness; ETX; Second— mentioned Trust & \begin{tabular}{} \end{tabular} & \
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[27] & RPL attacks & To combat RPL attacks, it includes a multidimensional and dynamic, trust model. & Simulation— Contiki/Cooja 3.0 & ✓ & QPC; QoS; Contextual information & Rank; Sybil; Blackhole; and the network. \\ \hline
[59] & IoT Protocols Security/IoT nodes/IoT networks & A protocol based on fuzzy logic, and a secure messaging system is developed. & Simulation— Contiki/Cooja & ✗ & Direct trust; Indirect trust; Routing score & \
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Table 2: Related Work for Trust-Based Methods for Routing Security. As compared to the traditional security solutions, the use of trust in IoT networks can reduce the uncertainty factor for nodes interconnection. The trust models proposed for IoT lack certain characteristics, including heterogeneity, dynamicity, and resource-constrained nature of IoT [62]. Some trust models involve computationally expensive IDS-based approaches for attacks detection, which require a hardware security chip embedded in the device [26]. Unlike existing research, a comprehensive trust and mobility-based routing protocol is proposed that considers the high-impact attacks, such as Rank and Blackhole attacks, node mobility in an IoT environment, and the selection of appropriate trust as well as mobility-based metrics for an effective security solution for RPL-based IoT networks. In proposed SMTrust secure routing protocol, the trust is computed considering the appropriate trust metrics, including the mobility-based metrics for nodes. This will facilitate the trust relationship between the nodes based on their mobility scenarios. Moreover, our proposed protocol is evaluated in static as well mobile scenarios for performance, considering the high impact attacks, such as Blackhole (WSN-inherited attack) and Rank (RPL-specific attack) attacks. The proposed solution, SMTrust, is different from the related methods basically for considering mobility metrics for trust computation, evaluation, and enhanced performance for static and mobile IoT environments.