Securing the IoT using Blockchain

Because it is a useful component in the modern world, the IoT has attracted a lot of attention, not only in terms of the variety of its usages but also as a potential attack surface. IoT users have increased at different levels. So. the amount of valuable data stored and processed in these devices has also increased. Understanding IoT security threats first requires a comprehensive grasp of the infrastructure. This section discusses the IoT infrastructure, its security threats, and proposed solutions through using blockchain [32].

IoT Infrastructure

With the proliferation of advanced technologies, internet availability has become widespread. This enables devices with built-in sensors to create a network of interrelated devices for efficient data transmission and communication, giving rise to the whole new world of the IoT. In simple terms, the IoT refers to a system of interlinked devices that can communicate and exchange critical information via the internet [33,34]. The large variety of internet-connected smart devices in the IoT needs an infrastructure. To unify the different components of the IoT in one network, there are four stages, as follows:

Stage One: Sensors/Actuators

This stage is also known as the sensor/perception layer, which consists of both wired and wireless sensors and smart devices. The components of this layer perceive information from the surrounding environment The information is converted to electrical signals and passed to the actuator. The raw data is transmitted to IoT gateways. There are several types of sensors, such as body sensors, environmental sensors, home sensors, etc. For data transmission, initially, a heterogeneous network connectivity must be assured, which includes a local area network (LAN), Wi-Fi, and Ethernet. A personal area network (PAN) is another type of LAN that consists of both wired and wireless communication protocols, such as Bluetooth. ZigBee etc.

Stage 2: The Internet Gateways

Also called the network layer, this layer is responsible for processing, controlling, and managing IoT data. The architecture of this network model must maintain communication performance overall for latency, error probability, scalability, bandwidth requirements, and security, while ensuring efficient energy usage. An internet gateway is like an intermediary networking device, which aggregates data from the sensors and maintains security protocols to route it securely through Wi-Fi, the Internet, and wired LANs and transfer it to a remote server, such as the cloud.

Stage 3: Edge IT and the Cloud

Also known as the Middleware layer of the IoT architecture, the edge computing IT system receives an enormous amount of preprocessed IoT data from the previous stages. This layer is responsible for data storage, analysis, and real-time processing. For this reason, various technologies are enabled, such as databases, the cloud, and big data processing models. Edge computing leverages the power of distributed local servers to facilitate computing and manage a wide range of services. An edge IT processing system usually resides close to the end-devices, to minimize communication latency, bandwidth, and overhead traffic away from a centralized cloud [35]. The enormous amount of IoT data can quickly eat up network bandwidth, engulfing data center resources. Here, the edge comes to rescue. It reduces the burden on IT infrastructure by performing some analytics beforehand. The processed data is forwarded to the cloud.

Stage 4: Applications Domain

The application layer of the IoT architecture deals with the application services of the IoT in the physical world. The classification of application services can be made based on the heterogeneity and availability of networks, along with the network coverage size. Application sectors include the military, the environment, transportation, energy, health care, smart cities, etc. [36,37]. Horizontal markets include supply chain management, asset management, fleet management, surveillance, etc.

Security Issues in the IoT and Solutions Using Blockchain

IoT devices and networks face several types of attacks due to a centralized structure, device capability, protocol design, and many other reasons. As security threats, attack techniques, and attack characteristics increase, researchers are trying to mitigate those attacks. These attacks breach the confidentiality, authenticity, and availability of IoT service [38]. In the case of industrial usage, this becomes a huge problem. Blockchain is a relatively new technology that possesses unique characteristics suitable for addressing IoT security issues [39]. In this section, the attacks and their proposed countermeasures using blockchain technology are discussed.