IoT devices are all around us, from kitchen appliances to automobiles. This makes them highly prone to hacking as they provide all the necessary data on demand. Thus, protecting IoT devices has become very challenging, thanks to the increasing technological demands of the electronics sector.
To create compelling and secure microcontroller software for such IoT devices, businesses must opt for high-quality microcontrollers and other equipment that will provide the best solutions and practices for microcontroller security in order to improve overall IoT device security.
Attacks on IoT devices can be divided into three categories depending on their targets as follows.
Software-based attacks target the application that manages the devices. By searching for software design and code vulnerabilities, an attacker can remotely attack the software of an embedded system to access data or gain control.
Since a software-based attack doesn’t require specific knowledge from hackers, they can use typical attacks like deploying malware and brute-forcing.
The most widespread software-based attacks involve the following:
- Brute-forcing access
- Buffer overflow
- Web application security exploitation
This attack exploits network infrastructure vulnerabilities. Such vulnerabilities result in hackers listening for, intercepting, and modifying traffic transmitted by an embedded system.
The most common network-based attacks are the following:
- Domain name system (DNS)
- Denial of service (DDoS)
- Signal jamming
- Man in the middle (MITM)
- Session hijacking
A side-channel attack is the most demanding and expensive type of IoT attack, requiring precise knowledge of the system’s hardware design and physical availability. Such attacks primarily use hardware security flaws in embedded systems for hacking.
As a result, hackers may work out the internal operation of a system and connected devices, steal cryptographic keys, or obtain control over the system itself.
The most common side-channel attacks are the following:
- Power analysis
- Electromagnetic analysis
- Timing attacks
There are multiple types of microcontrollers that offer plenty of solutions to prevent cyber threats, such as those mentioned above.
The solutions listed below are some of the primary and most popular tools used by the most successful businesses and organizations within the electronics sector.
Establishing a Root of Trust (RoT)
A root of trust (RoT) consists of a device’s identity and cryptographic keys. Therefore, an RoT number is the most fundamental building block for a secure IoT network.
RoTs for microcontrollers are typically created using a random number generator (RNG) and placing the identities and keys into the devices using a key injection process.
The IP can also be embedded into semiconductor chips during manufacturing without requiring changes to the standard CMOS process flow. Firmware can then be injected into each microcontroller using a standard programmer. The combination of IP and firmware enables multiple random identities and corresponding keys to be created on-demand throughout the device lifecycle.
Microcontroller firmware is low-level software that runs on microcontrollers. It typically interacts directly with the hardware to manage the device’s operations, such as reading sensors, controlling actuators, and communicating with other devices.
Furthermore, firmware verification refers to the microcontroller’s ability to validate software before execution, in which firmware components validate each other to ensure that the system only runs authenticated firmware.
Enabling a Memory Protection Unit (MPU)
The memory protection unit (MPU) is a microcontroller hardware that enables memory protection for memory regions varying for each chipset. These regions consist of subregions and could be as little as a few bytes long, solely allowing privileged access.
Moreover, it is harder to separate sections that the software can access at runtime in a system without virtual address mapping. The MPU separates sections in microcontroller memory by setting local permissions and attributes. Such a mechanism prevents access to the memory when the CPU, a type of processor, runs in user mode or prevents getting code from RAM.
Creating Software Isolation
Software isolation refers to keeping multiple software instances separated from one another to allow each instance to see and affect only itself. It aims to prevent a given process from spying on the execution of another process and thereby protect the occurrence of incorrect memory management implementation.
It is basically a runtime mechanism protecting different processes from each other, namely interprocess protection. These processes can be executed sequentially or concurrently.
This interprocess protection can also be extended to the flash memory and non-volatile data code.
Configuring Boot Protection
Boot protection is used to secure a system’s very first software instructions. Suppose an attacker succeeds in modifying the device boot address. In that case, he may be able to execute his code to bypass the initial dynamic protection configuration or to access unsecured bootloader applications that give access to the device memory.
A microcontroller usually allows the boot configuration in order to choose between starting at the bootloader application, at the user application, or the SRAM-located firmware. The boot protection relies on a single entry point to a trusted code that can be the user application or a secure service area. This type of hardware restriction protects the operating system from rootkits and helps prevent cyber threats that antivirus software may not detect.
As shown above, microcontrollers have many advantages and offer multiple solutions for the IoT device security issues that may come up regarding IoT devices. Therefore, developing secure microcontroller software and implementing the required functionality is vital in order to prevent cyber threats.
Although threats may come from multiple sources and in different ways, there is a wide product portfolio offering different types of microcontrollers that can maintain and provide IoT device security, assuring fast and secure microcontroller operations.