# Secure and Dynamic Memory Management Architecture for Virtualization Technologies in IoT Devices
## 1 Introduction  
The internet can be defined as a vast network connecting computing devices that are distributed throughout different areas of the universe. Real-world objects such as cars, air conditioners, refrigerators, and others that connected to the internet with the help of internet-enabled embedded devices are called the Internet of Things (IoT). The internet communication infrastructure has evolved and grown immensely since its inception in the early 1990s, and we perceive its growth as a process with four marked stages as illustrated in Table 1.  
The fast growth of the internet is popularly understood to have been caused by rapid advancements in two fields--networking technology and embedded device technology. In the first three stages of the development of networking, the diversity of devices connected to the internet was limited to servers, desktops, laptops, and mobile phones. Hence, the volume of data to be processed on the internet was limited and could be structured using standard databases. The fourth growth stage of the internet led to the pervading of the web into day-to-day life objects, manifesting as the new era of technology called the Internet of Things (IoT) Era. Due to the evolution of the IoT, the diversity of objects on the internet grew from home appliances to automobiles, and consequently increased the volume of data to be processed on the internet. Moreover, the diverse nature of this information made it unsuitable for a structured database. With that, the vulnerability of the information and infrastructure multiplied manifold. We start with our view of the IoT as a layered information flow infrastructure. According to our perception, the general structure of the IoT and the flow of information can be depicted as a six-layer architecture as shown in Figure 1. The first layer, _Information_, describes the real-time information about an object. For example, temperature, speed, humidity, sound, and similar parameters could be the types of information. Information can be real information or virtual information stored in devices like Radio-Frequency Identifications (RFIDs) and bar-codes. The information about the actual objects is fetched in the second layer of the IoT architecture, _Fetch_. Devices like sensors, RFID readers, and bar-code readers are used to carry the information, and comprise the Fetch stage. In a single IoT device, different information fetching devices can be available. In the next layer, _Communicate_, this information is transferred to the processing unit. The information can be transferred between the fetching device and the processing device through wired or wireless medium. The communicated data are processed in the next level of architecture, \begin{table}
\begin{tabular}{c c c} \hline \hline
**Stage** & **Devices** & **Connectivity** \\ \hline Mammoth Era & Desktops, Servers & Ethernet \\ \hline Mobile Computers Era & Laptops, Notebooks & Wifi, Bluetooth \\ \hline Smartphone Era & Mobiles, Smartphones & GPRS, 3G, 4G \\ \hline Internet of Things Era & TVs, Fridges, Watches & Bluetooth, Zigbee, Wifi, 3G, 4G \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Stages of development of the internet communication infrastructure. Figure 1: Information flow in the Internet of Things (IoT) architecture. Process.Processing can be done either in an embedded device or a method available on the internet (i.e., Cloud). The fifth layer, _Store_, keeps all the data in a structured manner. The storage can be a database server or a cloud server. The sixth layer, _Exhibit_, displays this stored information to the end-user based on the requirements of the user through relevant applications. Applications can be web applications, Android applications, or can be based on real-time operating systems (RTOSs) such as RTlinux or something equivalent. Unlike the devices available in the previous era, the impact of a security attack on IoT devices is enormous, as they directly connect to real-life objects like TVs, air conditioners, cars, etc.