IoT Hardware and Cybersecurity

A typical IoT architecture consists of the physical layer, which consists of IoT sensors and actuators, which may be connected in the form of a star, linear, mesh, or tree network topology. The IoT devices can process the data collected by the IoT sensors at the physical layer or send it to the fog/cloud computing layers for analysis through IoT access and Internet core networks. The Fog/cloud computing nodes perform lightweight or advanced analytics on the data, and the result may be sent to users for decision-making or IoT actuators to perform a specific task or control a given system or process. This implies that in an IoT infrastructure, we may have IoT devices, wireless access points, gateways, fog computing nodes, internet routers and switches, telecommunication transmission equipment, cellular base stations, servers, databases, cloud computing nodes, mobile applications, and web applications. All these hardware devices and applications constitute attack surfaces that cybercriminals can target to compromise IoT devices.

In implementing IoT security, it is vital to consider the kind of hardware found in IoT systems, from the IoT device level through the IoT networks, fog computing nodes, and internet core networks to the cloud. Security of traditional internet and cloud-based infrastructure is very complex but less challenging due to the massive amount of computing and communication resources that are deployed to handle cybersecurity algorithms and applications that are used to eliminate vulnerabilities, detect and prevent cyberattacks to ensure the confidentiality, integrity, and availability of data and information systems. In the case of IoT devices, the computing and communication resources are very limited due to the limited energy required to power the IoT device. Hence, energy-hungry and computationally expensive cybersecurity algorithms and applications can not be used to secure IoT nodes. This hardware limitation makes IoT devices vulnerable to cyberattacks and easy to compromise.

IoT devices are vulnerable to certain types of security attacks due to the nature of IoT hardware. Some of these vulnerabilities or weaknesses resulting from IoT hardware limitations include:

• The confidentiality and integrity of sensitive data collected by sensor devices can easily be compromised due to a lack of appropriate cryptographic algorithms or weak cryptographic algorithms. It is difficult to implement strong cryptographic algorithms that are difficult to be compromised by cybercriminals due to limited computing resources in IoT devices. IoT devices use microcontrollers for computing, which cannot handle strong but computationally expensive cryptographic algorithms. This makes IoT devices vulnerable to man-in-the-middle attacks where the wireless IoT traffic can be captured by cybercriminals and analysed to access it if it is not encrypted or if the encryption scheme is weak.
• Device manufacturers introduce some of the vulnerabilities of IoT devices. They are often focused on minimising the cost of the devices and the time to market, paying little or no attention to the security requirements or needs of the customers sometimes because customers are often concerned about the devices' prices, ease of use and functionalities. In this way, they sometimes ship devices with default passwords, no encryption algorithms implemented, and sometimes without any mechanisms for authentication. This makes the devices vulnerable to attacks.
• In some IoT deployments, the IoT devices share the same communication channels, making them vulnerable to packet collision attacks, where compromised IoT devices are used to create packet collisions on the channels, forcing the device to deplete its stored energy rapidly and may eventually shut down the device.
• Since the communication between the IoT devices and between the IoT devices and the access point or gateway is through wireless radio communication channels, the IoT devices are vulnerable to jamming attacks designed to force them to deplete their stored energy rapidly.
• IoT devices are also vulnerable to flooding attacks designed to flood IoT devices with benign or useless packets, so they will spend more energy processing these useless packets, rapidly depleting their stored energy and eventually shutting down the device.
• Since IoT devices are relatively easy to infect with malware, they are vulnerable to a kind of malware attack in which the attacker infects the device with malware that forces the device to perform more computations, rapidly depleting the energy stored in the device and eventually shutting it down.
• Another type of IoT hardware vulnerability is route poisoning, in which the attacker creates routing loops, turns some devices into sinkholes, or increases routing paths to force the devices to spend more energy and eventually deplete their energy, reducing the lifetime of some devices in the network.
• IoT devices can easily be infected and turned into botnets, which can then be used to conduct sophisticated large-scale attacks, such as distributed denial of service attacks, which can paralyse IT assets (servers and gateways).
• Another IoT hardware vulnerability is the lack of visibility. Many IoT devices are deployed without appropriate identification numbers (IP addresses), creating blind spots because the devices are not visible to security monitoring tools and can be exploited. Also, the fact that various devices may have different protocols makes monitoring all the devices within the network challenging, making them weak points.
• An inefficient firmware verification mechanism allows tampering with or reverse-engineering the firmware, making the device vulnerable to attacks. Attackers may illegally update the device's firmware or tamper with it so that they can easily capture it and use it for further attacks.
• Due to poor device management strategies, some organisations or individuals sometimes fail to attend to some devices to ensure that they are well-secured (failing to install necessary updates and patch security holes to gaps), leaving them vulnerable to attacks from cybercriminals.
• Some hardware security vulnerabilities are hard to eliminate, such as side-channel attacks, reverse engineering of the hardware, malware infection, and data extraction, which could be exploited and result in a data breach.
• IoT devices are vulnerable to physical attacks. A criminal can destroy or vandalise them and even access them manually.

IoT hardware attacks are the various ways that security weaknesses resulting from limitations in IoT hardware can be exploited to compromise the security of IoT data and systems. An attacker may install malware on IoT devices, manipulate their functionality, or exploit their weaknesses to gain access to steal or damage data, degrade the quality of services, or disrupt the services. An attack could conduct an IoT on devices to use them for a more sophisticated large-scale attack on ICT infrastructures and critical systems. There is an increase in the scale and frequency of IoT attacks due to the rise in IoT attack surfaces, the ease with which IoT devices can be compromised, and the integration of IoT devices into existing systems and critical infrastructure. Some of the common IoT hardware attacks include:

• Unauthorised access: Some IoT device manufacturers use weak or no security mechanisms to minimise manufacturing costs and reduce the time to market to meet the increase in market demand. They sometimes do not provide mechanisms for necessary updates to patch up security holes. Some create backdoors for remote servicing, which malicious hackers can exploit. In contrast, others use default or no passwords, making it easier for attackers to access and exploit the device to escalate their attacks.
• Emulation of fake IoT devices: A third party that knows the communication protocol could develop software to emulate standard functionalities between IoT devices and then get the leverage to share false information.
• Identity Theft: An attacker could steal the identification of legitimate devices and then perform malicious actions within the network without being identified.
• Injection of fake information: An attacker can inject fake or misleading information to disrupt the intended functionalities. For example, in a food supply chain, a third party could inject false information about the ethylene sensor and make the system think that the transported commodity is already rotten. Therefore, mechanisms must be implemented to protect the system from fake information injection.
• Firmware-base attacks: When a new security threat is discovered, a new firmware update is required to obtain an updated version to address the security threat. The firmware, security configuration and other device features can be cloned. The attacker can also upgrade the firmware of a device with malicious software ^[1]. The firmware, security configuration and other device features can be cloned. The attacker can also upgrade the firmware of a device with malicious software ^[2].
• Eavesdropping and man-in-the-middle attacks: Data exchange should be performed securely, making data interception by a third party impossible. Traditional data encryption schemes cannot be implemented in IoT devices, requiring lightweight encryption, which is not straightforward and is sometimes ignored by manufacturers. Transmitting unencrypted IoT data, including security data, makes IoT networks susceptible to eavesdropping and man-in-the-middle attacks.
• Energy depletion attacks: In this kind of attack, an attacker tries to increase the energy consumption of a battery-powered IoT device significantly, drain the device's battery, and eventually shut down the device. Examples of such attacks include Denial of Sleep (DoS), flooding, a carousel, and stretch attacks ^[3].
• Vampire attacks: In this kind of attack, an attacker tries to increase the energy consumption of a battery-powered IoT device significantly, drain the device's battery, and eventually shut down the device. Examples of such attacks include Denial of Sleep (DoS), flooding, a carousel, and stretch attacks ^[4].
• Routing attacks: An attacker may manipulate the routing information of the devices to create routing loops, selectively forward packets or intend to use longer routes to increase energy consumption. Some routing attacks include sinkholes, selective forwarding, wormholes, and Sybil attacks ^[5].
• Jamming attacks: A denial of service attack in a shared wireless communication channel where a user may prevent other users from using the shared channel ^[6]. It is an attack targeting the IoT wireless network's physical or data link layer.
• Brut-force attacks: This kind of attack is aimed at obtaining the login credentials of the detail to gain unauthorised access to the device. For devices with fault passwords, commonly used passwords (e.g., admin), or weak passwords, attackers can access these credentials and use them to gain illegal access to IoT devices.
• DoD/DDoD attacks: Because adequate security mechanisms are not implemented to harden the security of IoT devices, they can easily be compromised. Many IoT devices can constitute an army of botnets to conduct DDoS attacks to saturate the buffers and other resources in the access points, fog nodes and cloud platforms.
• Packet collision attacks: This attack is typical in IoT applications where the devices share the wireless communication channel. An attacker can capture some of the devices and then use them to create packet collisions in the communication channel to disrupt the communication and force the devices to consume more energy by trying to transmit packets multiple times and increase the time the devices stay awake to perform communication (or decreases the sleep time of the device). This kind of attack is a type of energy depletion attack.
• Physical attack on the device: An IoT device may be physically manipulated or damaged to extract vital information. This is an essential aspect of IoT-based agriculture, as the IoT infrastructure in the fields can be vandalised.

It is tough to eliminate IoT hardware vulnerabilities due to the hardware resource constraint of IoT devices. Some of the measures for securing IoT devices and mitigating the risk posed by IoT security vulnerabilities include the following:

• Implementing lightweight encryption schemes on IoT devices: The data stored in the IoT devices (e.g., device authentication data and other sensitive data) should be encrypted to ensure its confidentiality and integrity are not compromised. The IoT data should be encrypted before being transmitted through any transmission medium. Since traditional cryptographic algorithms are computationally expensive and require strong and energy-hungry computing systems, it is preferable to implement lightweight cryptographic algorithms that require relatively less energy.
• Implementing robust authentication mechanisms on IoT devices: Robust authentication mechanisms should be implemented to restrict access to IoT devices and to ensure that all IoT devices that connect to access points and servers are authenticated. This ensures that access to critical resources like access points, gateways, and servers can be controlled to ensure the authenticity of the communication. It is also important to avoid purchasing devices with hardcoded passwords, change default passwords, and create strong passwords for devices.
• Configuring firewalls to protect devices from traffic-based attacks: The network's perimeter can be protected by implementing firewalls that reject malicious traffic at the network's edge. That is, it allows only traffic from legitimate sources and blocks traffic from sources deemed malicious. It can also be used to segment the network so that the IoT network can be isolated from other networks and attacks on IoT networks can not be spread to different networks. Software firewalls can be configured on individual devices to restrict traffic from unauthorised sources from reaching the devices.
• Ensure that the software and hardware components are not compromised: The software and hardware components used in IoT devices should be well-tested to ensure no security vulnerabilities that malicious attackers may exploit to compromise the security of the data and the devices. Security measures should be included at every stage of the device lifecycle to ensure that well-known vulnerabilities are resolved and that there are security strategies to ensure that the device and data security is not compromised.
• Implement dedicated security hardware to improve device security: Dedicated hardware components are designed specifically to perform security-related functions (e.g., secure communications, energy-efficient cryptographic functions, and key management) to ensure the devices' real-time security. Some dedicated hardware components can facilitate the implementation of a secure boot process and authentication operations. Another advantage of using dedicated IoT security hardware is that some are designed to strike a balance between the IoT hardware constraint, energy consumption, and security.
• Always verify the validity and trustworthiness of the software and firmware of IoT devices: Reliable mechanisms should be implemented to verify the validity and trustworthiness of the software and firmware of IoT devices. This way, we can check if the software or the device's operating system has been tampered with or manipulated so that the device is vulnerable to attacks.
• Regular security checks and updates: Mechanisms should be implemented to check if the device has been tampered with. The firmware and software of the device should also be updated and regulated to patch any security holes.
• Regular security audits should be performed: The IoT network should be regularly audited using vulnerability scanning and security auditing tools to ensure that IoT vulnerabilities (including hardware vulnerabilities) and threats can be detected and resolved before criminals can exploit them.
• Enforcement of security policies: Sound security policies should be designed and enforced to ensure that the IoT device and data are not easily compromised. For example, the principle of security by design was implemented when developing and implementing IoT hardware and software. All IoT devices must be identified, monitored continuously, and regularly audited to ensure that known vulnerabilities can be resolved on time. Attacks against IoT devices should also be detected and blocked on time.