# Defense and Security Mechanisms in the Internet of Things: A Review
## 3 Materials and Methods  
This part of the paper focuses on analysing the security procedures in IoT systems and the significant role of cryptography and the blockchain in protecting such systems. Since Internet of Things devices have already or will eventually be part of people's daily lives, addressing the security issue of these devices and data is crucial. This section deals with the theoretical side of IoT security, which will guide us to those cryptographical means whereby the communication in IoT networks is protected, including encryption, hash functions, and digital signatures. One efficient method to manage data is using blockchain technology, which can improve IoT security and become reliable in monitoring data integrity and decentralisation. In addition, we examine the hacks that have been made against IoT devices and the ways through which these threats can be identified and prevented. These basic concepts are crucial in developing and implementing secure IoT systems in various areas, including healthcare and industrial automation.  
IoT applications are diverse and can be found in various sectors such as healthcare, home, industry, and agriculture. The following subsections illustrate that each domain has security risks that require developing specific secure platforms and protocols. The information presented in Table 2 includes a list of platforms used in the IoT environments that can be used to integrate security and defense mechanisms.  
\begin{table}
\begin{tabular}{p{113.8 pt} p{113.8 pt} p{113.8 pt}} \hline \hline
**Platform** & **Application, Features, Security Enhancement** & **References** \\ \hline AWS IoT Core & \(\bullet\) & Industrial IoT (smart factories), smart home devices, healthcare monitoring & [38] \\  & \(\bullet\) & Provides scalable device management, edge computing capabilities, and secure communication & \\  & \(\bullet\) & Implementation authentication and key agreement protocols and integration of anomaly detection systems or IDSs to monitor data streams for unusual patterns & \\ \hline Microsoft Azure IoT & \(\bullet\) & Predictive maintenance, healthcare data analysis, retail inventory management & [39; 40] \\  & \(\bullet\) & Secure edge computing, device authentication, and robust analytics tools & \\  & \(\bullet\) & Using additional cryptographic protocols for data encryption, deploying intrusion detection systems to protect against DDoS and replay attacks & \\ \hline Google Cloud IoT & \(\bullet\) & Smart city infrastructure, agriculture (for example, irrigation control), and fleet management & [41] \\  & \(\bullet\) & Secure device connection, data processing at the edge, and scalability & \\  & \(\bullet\) & Strengthen session key agreement mechanisms to protect against temporary parameter leakage attacks, employing IDSs to detect anomalous traffic indicative of cyber-attacks & \\ \hline \hline \end{tabular}
\end{table}
Table 2: Summary of platforms that support IoT environments.  
The Internet of Things is a concept in which physical devices are connected to the Internet, allowing them to collect, exchange, and analyse data. These devices can communicate with each other, other systems, or the user. In IoT, devices often have built-in sensors and software that allow them to process data. IoT applications cover a wide spectrum. Some typical applications are smart homes, where devices such as refrigerators, thermostats, or light bulbs can be controlled using mobile applications or health monitoring systems that automatically send data to a doctor [44; 45; 46]. The diversity of these applications is presented as a word cloud in Figure 1, highlighting the scale and varied impact of IoT technologies.  
This paper considers that the aspect of communication in IoT is significant because of the interconnectedness of devices. It consists of several protocols and technologies depending on the application type and the requirements. The security of communication in IoT environments is achieved through the implementation of various cryptographic protocols as outlined in [1].