# IoT Intrusion Detection Taxonomy, Reference Architecture, and Analyses
## 3 IoT Security Challenges  
One important challenge reported in the literature [2; 3; 4; 5; 7; 8; 9; 10; 11; 12; 13] is securing IoT technologies, which can be life threatening. A harmful scenario can result with Integrated Smart-Devices (ISD) when exploited by hackers, especially in industrial IoT applications or Internet of Vehicles (IoV). There is a number of IoT technology-hacking scenarios as illustrated in [41; 42] that could cause a high level of harm to the system. IoT information security issues are associated with the preservation of authentication, authorization, integrity, confidentiality, non-repudiation, availability, and privacy [43; 44]. Security issues and challenges related to IoT technologies can be approached from aspects of issues associated with different IoT layers. Some studies [4; 6; 45] have proposed security requirements for each layer within the IoT architecture separately, whereas some other references [8; 12; 27; 28; 29] remain focused on analysis and presentation of the potential threats that attack each layer. This paper seeks to combine security requirements against threats to propose a three-layer IoT architecture. Accordingly, the most basic IoT architecture, the three-layered architecture, provides a simple platform from which to present security requirements and concerns as well as threats/exploits at each layer of the architecture as illustrated by considering Table 2 combined with Figure 2.  
The security requirements of Table 2 are defined here. Authentication is confirming the identity of a claimer. Thus, in IoT, each device is expected to have the ability to verify the identity of its user and another device for the interaction with others. Authorization is giving access to an entity to interact in the IoT environment. Integrity refers to maintaining the consistency, precision, and dependability of information, while confidentiality is about making sure that sensitive information is accessed by authorized entities. Non-repudiation guarantees holding an entity accountable for its actions. Availability ensures that IoT services are there and can be accessed from anywhere and anytime the user needs them. Privacy is a property and/or process of ensuring that private information is only accessible by authorized entities. The properties above, taken as requirements, should be enforced to achieve the highest levels of safety. However, IoT device constraints will naturally limit the extent and depth achievable, which therefore necessitates a risk assessment to understand better the threats, impacts, and tradeoffs. Figure 2 shows how active and/or passive threats can impact those aforementioned properties within the IoT ecosystem [12; 36; 37; 38].  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Layers** & **Attacks** & **Security Requirements** \\ \hline Application & Data accessibility and authentication, Data privacy & Privacy protection, Authentication, Information \\  & and identity, Dealing with availability & security management, \\ \hline Network & \begin{tabular}{c} Man-in-the-middle, Denial of service, \\ Eavesdropping/Sniffing, Routing attack. \\ \end{tabular} & \begin{tabular}{c} Authentication, Communication security, Key \\ management, Routing security, Intrusion detection, \\ \end{tabular} \\ \hline Perception & \
\begin{tabular}{c} Node capture, Denial of service, Denial of sleep, \\ Distributed denial of service, Fake node/Sybil, \\ Replay, Side channel, Mass node authentication, \\ \end{tabular} &
\begin{tabular}{c} Data confidentiality, Lightweight encryption, \\ Key management, Authentication. \\ \end{tabular} \\ \hline \hline \end{tabular}
\end{table}
Table 2: IoT architecture, attacks, and security requirements.