The Internet of Things (IoT) is a network of physical objects, or "smart objects", that are embedded with sensors, software, and other technologies to allow them to connect and exchange data with other devices and systems over the internet.
IoT devices can include phones, appliances, thermostats, lighting systems, security cameras, vehicles. Today, smart watches track exercise and steps, smart speakers add items to shopping lists and switch lights on and off, and transponders allow cars to pass through tollbooths.
The IoT simplifies and automates tasks that are complicated and sometimes beyond the scope of human capabilities. IoT devices can communicate with each other and with other internet-enabled devices, and can sense or interact with their internal states or the external environment. IoT can enable seamless communication between people, processes, and things, and can provide sensor information and improve quality control. It can also lead to automation, which can improve the quality of service, reduce waste and labor costs, and simplify decision-making.
However, IoT also presents some challenges, such as data security and equipment safety. Sensitive personal details of a user might be compromised when the devices are connected to the internet, and equipment in the huge IoT network may also be at risk.

Although examples of interconnected electronic devices exist as far back as the early 19th century, with the invention of the telegraph and its ability to transmit information by coded signal over distance, the origins of the IoT date to the late 1960s. It was then that a group of prominent researchers began exploring ways to connect computers and systems. A prime example of this work was ARPANET, the network created by the Advanced Research Projects Agency (ARPA) of the U.S. Defense Department; this network was a forerunner of today's Internet. In the late 1970s businesses, governments, and consumers began exploring ways to connect personal computers (PCs) and other machines to one another. By the 1980s local area networks (LANs) provided an effective and widely used way to communicate and share documents, data, and other information across a group of PCs in real time.
By the mid-1990s the Internet extended those capabilities globally, and researchers and technologists began exploring ways that humans and machines could better connect. In 1997 British technologist Kevin Ashton, cofounder of the Auto-ID Center at MIT, began exploring a technology framework, radio-frequency identification (RFID), that would allow physical devices to connect via microchips and wireless signals, and it was in a speech in 1999 that Ashton coined the phrase “the Internet of Things.” Within a few years' smartphones, cloud computing, advancements in processing power, and improved software algorithms had created a framework for collecting, storing, processing, and sharing data in a more robust way. At the same time, sophisticated sensors appeared that could measure motion, temperature, moisture levels, wind direction, sound, light, images, vibrations, and numerous other conditions—along with the ability to pinpoint a person or a device through geolocation. These developments made possible the ability to communicate with both digital devices and physical objects in real time. For example, by adding a tracking chip, such as an Apple AirTag to an object such as a wallet or suitcase, it is possible to view its location. The same chip built into a digital device can track its whereabouts if lost or stolen. Then, with the widespread adoption of mobile devices such as smartphones and tablets and the introduction of pervasive wireless connectivity, it was possible to connect people and things in a near ubiquitous way. As a result, smart traffic networks, connected storage tanks, and industrial robotics systems became the norm.
The IoT continues to evolve. Today it supports an array of use cases, including artificial intelligence used for ultrasophisticated simulations, sensing systems that detect pollutants in water supplies, and systems that monitor farm animals and crops. For example, it is now possible to track the location and health of animals and to apply remotely optimal levels of water, fertilizer, and pesticides to crops.
Highly connected systems allow shipping companies and airlines to factor in weather and mechanical problems and then optimize fleets for maximum loads and efficiencies. The IoT provides motorists with real-time maps and navigation suggestions that route and reroute them based on current traffic patterns. These systems reduce congestion and pollution and save time and money.

The architecture of IoT is divided into 4 different layers i.e. Sensing Layer, Network Layer, Data processing Layer, and Application Layer.

Sensing Layer: The sensing layer is the first layer of the Internet of Things architecture and is responsible for collecting data from different sources. This layer includes sensors and actuators that are placed in the environment to gather information about temperature, humidity, light, sound, and other physical parameters. Wired or wireless communication protocols connect these devices to the network layer.

Network Layer: The network layer of an IoT architecture is responsible for providing communication and connectivity between devices in the IoT system. It includes protocols and technologies that enable devices to connect and communicate with each other and with the wider internet. Examples of network technologies that are commonly used in IoT include WiFi, Bluetooth, Zigbee, and cellular networks such as 4G and 5G technology. Additionally, the network layer may include gateways and routers that act as intermediaries between devices and the wider internet, and may also include security features such as encryption and authentication to protect against unauthorized access.

Data processing Layer: The data processing layer of IoT architecture refers to the software and hardware components that are responsible for collecting, analyzing, and interpreting data from IoT devices. This layer is responsible for receiving raw data from the devices, processing it, and making it available for further analysis or action. The data processing layer includes a variety of technologies and tools, such as data management systems, analytics platforms, and machine learning algorithms. These tools are used to extract meaningful insights from the data and make decisions based on that data. Example of a technology used in the data processing layer is a data lake, which is a centralized repository for storing raw data from IoT devices.

Application Layer: The application layer of IoT architecture is the topmost layer that interacts directly with the end-user. It is responsible for providing user-friendly interfaces and functionalities that enable users to access and control IoT devices. This layer includes various software and applications such as mobile apps, web portals, and other user interfaces that are designed to interact with the underlying IoT infrastructure. The application layer also includes analytics and processing capabilities that allow data to be analyzed and transformed into meaningful insights. This can include machine learning algorithms, data visualization tools, and other advanced analytics capabilities.

An IoT framework can be defined as a set of protocols, tools, and standards that provide a specific structure for developing and deploying IoT applications and services.
The framework of IoT typically includes a combination of the following:

These components work together to enable the seamless integration of IoT devices (what is IoT) and systems. For example, the device management is necessary for updating and monitoring the performance of the device. Protocols allow the different connections between devices and the internet.
There needs to be a cloud platform where data will be processed and stored, this also connects with an application or platform that is in charge of displaying the data and allows other functions or services.

There are IoT frameworks that are open source, and others that are proprietary. IoT framework open source doesn't mean that it is free, many people get confused with this concept. We have even talked about IoT open source devices.
Open source frameworks are useful because they provide access to the code of the platform in order to make any modifications as needed and build the IoT application with more freedom. Finally, proprietary frameworks are IoT frameworks that don't grant access to the source code, they have an already established platform from which IoT product design and development consultants can start working.

AWS IoT, Azure IoT, IBM Watson IoT, KAA IoT, and Google IoT Core.

ThingsBoard, OpenHab, DeviceHive, Mainflux, and Eclipse IoT.

The IoT makes things around us more capable and responsive by connecting the physical and digital worlds. IoT offers several benefits in our daily lives. Following are some of its benefits:

IoT Objects are the physical devices or entities that are part of the Internet of Things ecosystem. These objects can be anything from simple sensors to complex machines.

IoT Services are the functions and capabilities provided by IoT objects. These services can range from basic data collection to complex analysis and automation.

The Internet of Things (IoT) consists of several structural components that enable communication and interaction between devices, systems, and networks. The following are key aspects of the IoT structure:

3. Data Processing Layer

These structural aspects of the IoT form the foundation for building and deploying IoT systems, enabling the collection, processing, and analysis of data from a vast array of devices and sensors.

The following environment characteristics of the Internet of Things (IoT) can be identified:

These environment characteristics of the IoT highlight the importance of sensors, data collection, scalability, energy efficiency, and intelligence in IoT systems, as well as the need for security, complexity management, and dynamic adaptation to changing environmental conditions.

The following key traffic characteristics of the Internet of Things (IoT) devices:

As the number of IoT devices grows exponentially, scalability becomes a critical consideration to ensure seamless integration, efficient data processing, and secure communication.

Interoperability refers to the ability of different devices, services, and systems to seamlessly exchange data and integrate with each other. This enables faster and more efficient communication between components inside an IoT framework.

The rapid growth of IoT devices has raised significant concerns about their security and privacy. With billions of devices connected to the internet, the potential attack surface is vast, and the risk of data breaches and unauthorized access is high.

The Open Architecture refers to a framework that specifies the physical elements, network technical arrangement, and setup, operating procedures, and data formats to be used in IoT systems. This architecture is designed to be flexible, modular, and scalable, allowing for the integration of diverse IoT devices, networks, and applications.

The following are the key IoT technologies:

Communication Technologies

Device Intelligence is a crucial aspect of the Internet of Things (IoT), enabling organizations to effectively manage and secure the vast number of connected devices. In the context of IoT, Device Intelligence refers to the ability to collect, analyze, and utilize data from devices to understand their behavior, context, and potential risks.

Communication capabilities are essential for the seamless operation of IoT systems, enabling devices to connect, share data, and interact effectively. IoT devices rely on various communication protocols to interact with each other and external systems. The top 6 IoT communication protocols are:

Mobility support refers to the ability of devices and systems to maintain connectivity and functionality while moving or changing their location. This is crucial in IoT applications where devices are often deployed in diverse environments, such as homes, industries, or public spaces, and need to maintain seamless communication with other devices, networks, and the cloud.

Device power is a crucial aspect of Internet of Things (IoT) design, as it directly impacts the device's lifespan, maintenance, and overall cost. Here are the key options and considerations for powering IoT devices:

Sensors play a crucial role in the Internet of Things (IoT) ecosystem, enabling devices to perceive and respond to their environment. Here's an overview of sensor technology in IoT:

Radio Frequency Identification (RFID) technology plays a significant role in the Internet of Things (IoT) ecosystem, enabling the automatic identification and tracking of objects, people, and animals. Here are key aspects of RFID technology in IoT:

Satellite IoT uses satellite networks to facilitate global connectivity, serving as a standalone solution or a complement to terrestrial networks such as cellular connectivity. It is particularly valuable in remote or hard-to-reach areas where traditional connectivity options are limited or non-existent.

IoT protocols are a set of standards and rules that facilitate information exchange and Machine-to-Machine (M2M) communication between devices in an IoT network. They ensure that devices can understand each other and exchange data efficiently, securely, and reliably.

Protocol standardization for IoT refers to the process of establishing common, universally accepted communication protocols and data formats for devices and systems to exchange information seamlessly across different networks, applications, and industries. This ensures interoperability, allowing devices from various manufacturers to communicate with each other, and with cloud-based services, without vendor lock-in or proprietary limitations.

In the IoT, protocol standardization is crucial for ensuring interoperability, scalability, and security. Without standardized protocols, devices from different manufacturers may not be able to communicate with each other, hindering the widespread adoption of IoT technologies.

Efforts refer to the collaborative work by various organizations, industry groups, and researchers to develop, standardize, and improve communication protocols that enable the smooth functioning of IoT systems. These efforts are crucial because IoT devices are diverse, often use different communication methods, and operate under various conditions. Standardized protocols ensure interoperability, security, and scalability, which are essential for the widespread adoption and success of IoT technologies.
Here's a summary of the efforts made in developing and refining these protocols:

M2M protocols enable direct communication between devices, machines, or sensors without human intervention. They are designed for low-power, low-bandwidth, and low-latency communication, often using wireless technologies. Key characteristics of M2M protocols include:

WSN protocols enable communication between sensor nodes and a central gateway or sink node in a wireless sensor network. Key characteristics of WSN protocols include:

SCADA systems are used to monitor and control industrial processes, such as power grids, water treatment plants, and manufacturing facilities, remotely. SCADA protocols enable communication between the central control unit and remote devices, ensuring secure and reliable data transmission. Commonly used SCADA protocols include:

RFID protocols define how tags and readers communicate with each other, transmitting data wirelessly. Commonly used RFID protocols include:

Unified data standards protocols refer to the sets of rules, guidelines, and specifications that enable different systems, applications, and devices to communicate and exchange data seamlessly. These protocols ensure that data is represented, exchanged, and processed consistently across various platforms, networks, and organizations.

IEEE 802.15.4 is a technical standard that defines the operation of Low-Rate Wireless Personal Area Networks (LR-WPANs). It specifies the physical layer (PHY) and media access control (MAC) for LR-WPANs, enabling low-power, low-data-rate wireless communication between devices.

BACnet (Building Automation and Control Network) is a data communication protocol used in building automation systems (BAS) to control the exchange of information between different devices and components. Developed by the American Society of Heating, Refrigerating, and Air-Conditioning Engineers (ASHRAE) in 1987, BACnet is a widely adopted standard for building automation and control systems.

Modbus is a widely used, open-standard, serial communication protocol for industrial electronic devices, particularly in industrial automation and control systems. It was originally developed by Modicon (now Schneider Electric) in 1979 and has since become a de facto standard for communication between devices in industrial settings.

The Zigbee architecture is a layered protocol stack that enables low-power, low-data-rate wireless communication for IoT devices. It is based on the IEEE 802.15.4 standard and consists of six layers:

The network layer is a crucial component in IoT architecture, responsible for transmitting and processing sensor data. It sits between the Physical/Device Layer and the Application Layer, facilitating communication between devices and the internet or other networks.

6LoWPAN (IPv6 over Low-power Wireless Personal Area Networks) is a standard protocol for enabling IPv6 communication on wireless networks composed of low-power wireless modules. It is designed to bring the benefits of standard IP networking to low-power mesh and sensor networks, which often used proprietary technologies.

The Constrained Application Protocol (CoAP) is a specialized web transfer protocol designed for use with constrained nodes and constrained networks in the Internet of Things (IoT). CoAP is intended for devices with limited resources, such as memory, processing power, and energy, commonly found in IoT devices.

IoT security refers to the practice of protecting Internet of Things (IoT) devices and networks from unauthorized access, use, disclosure, disruption, modification, or destruction. Given the vast number of IoT devices and their diverse communication protocols, securing IoT requires a multifaceted approach.

The Raspberry Pi is a series of small, affordable, and highly capable single-board computers. It was initially developed in the UK by the Raspberry Pi Foundation to promote the teaching of basic computer science in schools.
Raspberry Pi boards are used in a wide range of applications, from learning programming skills and building hardware projects, to home automation, industrial automation, and IoT explorations. They run on Linux and have GPIO pins for controlling electronic components, making them versatile tools for both beginners and experts in the field of computing and electronics.

Building an Internet of Things (IoT) project with a Raspberry Pi is a powerful and accessible way to create smart devices that can collect, process, and share data. Thanks to the Raspberry Pi's flexibility, we can connect various sensors and devices to the internet to monitor and control different environments.
Building an IoT project with a Raspberry Pi involves several steps. Here's a brief overview:

An IoT system is a network of interconnected physical devices, vehicles, buildings, and other objects that are embedded with sensors, software, and other technologies to collect and exchange data over the internet.
IoT systems typically consist of four main components:

IoT systems can bring numerous benefits, such as increased automation, efficiency, and convenience, but they also pose challenges related to security, privacy, and interoperability. It's essential to consider these factors when designing and implementing IoT systems.

In the context of IoT with Raspberry Pi, logical design using Python involves planning the software architecture and writing Python code to orchestrate the interactions between the Raspberry Pi, sensors, and other devices. Here's a brief outline:

IoT physical devices and endpoints are objects connected to the Internet that can send and receive data. These devices can be any object with unique identifiers and the ability to interact with the physical environment. They are equipped with sensors, actuators, communication modules, and analysis and processing capabilities.

Raspberry Pi as an IoT Device:
Raspberry Pi, a low-cost mini-computer, can be used as an IoT device due to its Linux-based operating system and support for Python programming. Its GPIO pins provide capability for attaching sensors and actuators, making it a popular platform for IoT projects.

An IoT device is a hardware component that connects wirelessly to the internet or a local network hub, enabling remote monitoring, control, and communication with other devices. These devices are embedded with sensors, processing ability, software, and other technologies that allow them to collect and exchange data with other devices and systems over the internet or other communication networks.

Examples
Smart home devices, Industrial devices, Consumer devices, Enterprise devices

The building blocks of Raspberry Pi can be summarized as follows:

These components work together to form the foundation of the Raspberry Pi, enabling its functionality as a small single-board computer (SBC) capable of running a variety of operating systems and applications.

Visit Raspberry Pi page.

The Raspberry Pi, a small and affordable single-board computer, can run a variety of Linux distributions. Here are some key points to consider:

Supported Devices
Raspberry Pi 4, 5, and other models are supported by various Linux distributions, including Ubuntu, Ubuntu Core, and others.

Popular Linux Distributions for Raspberry Pi

The Raspberry Pi offers various interfaces for connecting peripherals, sensors, and displays. Here's a summary of the interfaces mentioned:

    import RPi.GPIO as GPIO
    import time
    # Set up GPIO
    GPIO.setmode(GPIO.BCM)  # Use Broadcom pin-numbering
    GPIO.setup(18, GPIO.OUT)  # Set GPIO 18 as an output pin
        try:
            while True:
            GPIO.output(18, GPIO.HIGH)   # Turn on LED
            time.sleep(1)    # Wait 1 second
            GPIO.output(18, GPIO.LOW)   # Turn off LED
            time.sleep(1)     # Wait 1 second
        except KeyboardInterrupt:
            pass 	# Exit loop when CTRL+C is pressed
        finally:
        GPIO.cleanup()	  # Reset GPIO settings

The following are the some vulnerabilities of IoT:

1. Device Authentication
To prevent unauthorized devices from accessing the IoT network or interacting with other devices - IoT devices must have secure methods for verifying their identity when connecting to networks and other devices. Examples: Using digital certificates, strong passwords, biometrics, or hardware-based authentication.

2. Data Encryption
To prevents attackers from eavesdropping on communications or modifying data during transmission - Data transmitted between IoT devices and systems must be encrypted to protect it from being intercepted and tampered with. Examples: TLS (Transport Layer Security), AES (Advanced Encryption Standard), and SSL (Secure Sockets Layer).

3. Access Control
Using limits access to sensitive data and functionalities to prevent unauthorized manipulation - IoT systems should enforce strict access control policies to ensure that only authorized users and devices can access or modify data and functionalities. Examples: Role-based access control (RBAC), multi-factor authentication (MFA), and privilege management.

4. Secure Firmware Updates
To prevents attackers from exploiting known vulnerabilities in outdated firmware - IoT devices must have the ability to securely update their firmware to patch vulnerabilities and enhance functionality.Examples: Over-the-air (OTA) updates with integrity checks, cryptographic verification of updates.

5. Physical Security
To prevents attackers from directly accessing or altering the hardware to gain control or extract sensitive information - IoT devices must be protected against physical tampering, especially if deployed in public or insecure environments. Examples: Tamper-resistant designs, hardware security modules (HSM), and secure boot.

6. Data Integrity
To ensures that data is not altered or corrupted during transmission or storage - Mechanisms must be in place to ensure the integrity of data transmitted and stored by IoT devices. Examples: Hashing algorithms (e.g., SHA-256), cryptographic signatures, checksums.

7. Device Confidentiality
To prevents exposure of sensitive data, such as personal information, device configurations, and cryptographic keys - Sensitive information stored on or transmitted by IoT devices must remain confidential. Examples: Data encryption at rest and in transit, secure key storage, data anonymization.

8. Security Monitoring and Logging
To identify suspicious activity and enables quick response to breaches - IoT devices and networks should have logging and monitoring capabilities to detect and respond to security incidents in real-time. Examples: Intrusion detection systems (IDS), activity logs, and anomaly detection.

IoT threat analysis is the process of identifying, evaluating, and prioritizing potential threats that can target IoT devices, networks, and ecosystems. This analysis is essential to understanding the vulnerabilities in IoT systems and developing security strategies to mitigate these risks.

To mitigate IoT security threats, consider the following best practices:

Here are some examples of IoT use cases:

Misuse cases in IoT highlight potential system behaviors that stakeholders consider unacceptable or insecure. Here are some examples:

IoT security tomography refers to the process of analyzing and visualizing the security posture of an IoT system, much like medical tomography visualizes internal structures of the human body. This involves identifying vulnerabilities, threats, and potential attack paths across multiple layers of an IoT system.

The layered attacker model is a framework for understanding and mitigating attacks on IoT systems. It consists of multiple layers, each with its own set of vulnerabilities and attack vectors:

Identity establishment refers to the process of verifying and authenticating the identity of IoT devices, ensuring secure communication, and protecting data integrity. This is crucial in preventing unauthorized access, man-in-the-middle attacks, and data breaches.

Access control in IoT refers to the mechanisms and policies that regulate the interaction between devices, users, and data in an Internet of Things (IoT) ecosystem. It ensures that only authorized devices and users can access and manipulate sensitive information, preventing unauthorized access, data breaches, and malicious activities.

By implementing these best practices and addressing the challenges and solutions outlined above, IoT systems can ensure robust and scalable access control, protecting sensitive data and preventing unauthorized access.

Message integrity in IoT refers to the assurance that data transmitted between devices or systems has not been tampered with, modified, or corrupted during its wireless transmission. This is crucial in IoT applications where data accuracy and completeness are essential for decision-making, control, and safety.

Non-Repudiation
Non-repudiation provides proof of the origin, authenticity, and integrity of data. It ensures that a sender cannot deny having sent a particular message, and a recipient cannot deny having received it. This is achieved through digital signatures, cryptographic hash functions, and other techniques that provide evidence of a message's existence and contents. Non-repudiation is crucial in legal and commercial contexts, where it helps resolve disputes and ensures the validity of contracts and agreements.

Availability
Availability refers to the ability of a system or network to provide access to data and services when needed. It ensures that data is readily accessible, and communication channels remain open, even in the presence of faults or failures. Availability is critical in ensuring business continuity, as it enables organizations to maintain operations and respond to changing circumstances.

The bellow are the some important security model for Internet of Things: