# Efficient Secure Routing Mechanisms for the Low-Powered IoT Network: A Literature Review
## 1 Introduction
The Internet has undergone remarkable changes that offer both extraordinary opportunities and significant difficulties for users; troubles emerge from unauthorized users utilizing cyberspace and exploiting its numerous weaknesses. Various cyber insights are required for the Internet to assess risks and overcome challenges [17]. The increasing proliferation of WSN devices in an actuating-communicating network has spawned the Internet of Things (IoT), in which data is seamlessly shared across platforms by fusing sensors and actuators with our surroundings. Medical and environmental monitoring can be automated using these low-cost WSN devices. RPL improves the utilization of these sensors in real-world applications by assessing their performance. Low-Power and Lossy Networks (LLNs) are mainly restricted nodes with limited processing power and fluctuating energy. Most traffic patterns are multipoint-to-point or multipoint-to-multipoint rather than point-to-point. As a result, data rates are often reduced, resulting in instability [18]. Contiki is an operating system that allows RPL and lossless monitoring of Internet of Things devices. Topological node assignment is based on multi-hop transmissions and has been employed in environmental monitoring, health care, and other smart systems [19]. Routing is a popular topic in the IoT community because of the limitations imposed by these devices. In many IoT networks, the Internet Engineering Task Force's (IETF) routing protocol for low power and lossy networks (LPN) has become the norm since it was intended to effectively utilize the finite resources of IoT devices while delivering effective routing services. RPL's architecture included many but optional security methods for ensuring reliable routing. Research on the security elements of RPL's routing protocol, such as routing assaults, novel mitigation mechanisms and intrusion detection systems (IDSs), and goal functions with an eye on security, has exploded since the protocol's 2012 standardization (OPs). The impacts of RPL's security features against routing assaults have not yet been studied, which is strange. RPL's security features have not been implemented in any of the existing IoT operating systems (OSs), such as Contiki OS and TinyOS. RPL security features have been partially implemented in Contiki OS, with the addition of a preloaded secure mode (PSM) and an optional replay protection system. Using this approach, we were able to provide the groundwork for this paper. We summarize our contributions as follows. We confirmed that, except for the wormhole, RPL in the preinstalled secure mode (PSM) could prevent external adversaries from entering the IoT network for the examined attacks (WH). Additionally, we demonstrated that the optional replay protection offers superior protection against the neighbor attack (NA). However, it needs more optimization to minimize its impact on energy usage. We observed and assessed the effect of the examined assaults on the routing topology and offered two simple strategies for mitigating the consequences of the investigated attacks without using external security measures, such as intrusion detection systems or other security mechanisms. Another performance comparison of the suggested methodologies' implementation was undertaken. The findings indicated that RPL performed better in terms of end-to-end (E2E) latency and packet delivery rate (PDR) when subjected to Selective-Forward (SF) and Black-hole assaults. This paper explored the numerous security challenges in wireless sensor networks (WSNs) and the IoT. The function of the IoT in Industry 4.0 demonstrates how various automated systems can be used to optimize processes. Similarly, the IoT-LPN protocols are examined in this paper, which describes each protocol's strengths and weaknesses. This paper also discusses security objectives (availability, confidentiality, privacy, and so on), threats, and WSN and IoT-LPN problems.