With the rise of IoT and connected devices, our world is becoming more and more digital. From smart home appliances to industrial control systems, embedded systems power many of the technologies we interact with daily. However, as these systems get connected to networks, they also become vulnerable to cyber threats. In this article, you will explore some best practices to fortify embedded it solution against cybersecurity risks.
- Practice Secure Development
One of the most effective strategies is to include security into an embedded system at the development stage, as this creates the groundwork for a strong defense. To begin with, developers should conduct a comprehensive threat modeling exercise to identify potential system vulnerabilities and learn how attackers can exploit them. In order to identify any potential vulnerabilities, this entails examining all interfaces, functionalities, parts, and data flows.
The next step is to do static and dynamic source code analysis to find any security vulnerabilities, such as buffer overflows, injection problems, authentication faults, etc. While dynamic analysis runs the code and looks for abnormalities, static analysis examines the code without actually running it. Resolving problems now is far more cost-effective than retrofitting security later.
Limiting various features and functions to the minimal amount of access is in line with the least privilege concept. Disabling or removing any extra ports, radios, or peripherals that aren’t needed for the intended purpose is also advised. Rust and other memory-safe programming languages can help avoid many frequent memory-safety-related issues.
- Isolate Critical Components
Isolating critical components is a key practice to limit the impact of cyber attacks. Many embedded systems have distinct sections – interfaces that interact with external networks, and internal modules that control essential operations. By design, these sections need to communicate. However, if the external interface gets compromised, the attacker should not be able to affect the internal functions.
To achieve this, the different sections must be isolated using separate processors, different network segments, and distinct memory spaces. For example, the wireless radio on a vehicle ECU should be handled by a different microcontroller than those managing engine functions. Similarly, an IoT device’s user app and web server can run on one chip, isolated from the database processor managing device settings and firmware.
With proper isolation in place, even if an attacker gains control of the wireless radio or user app, they would not be able to access the internal network connecting safety components. This prevents malware from spreading across the system. Different processors, networks and memory boundaries make it difficult for attacks to jump from public interfaces to critical operational areas. Isolation reduces the overall attack surface and helps contain compromises to limited sections of the device. It protects critical operations from being brought down due to external vulnerabilities.
- Use Encrypted Authentication
For embedded systems to securely communicate and establish trust with external entities, strong authentication is paramount. This involves verifying the identity of both sides before an interaction can take place. Public-key cryptography provides a robust mechanism for mutual authentication between devices and backend servers.
Each device and server holds a public/private key pair. During the handshake, devices and servers exchange and verify digital signatures to confirm they are communicating with the correct peer. This prevents man-in-the-middle attacks. Encrypted protocols are used to secure the connection and encrypt all data transferred over external networks.
In addition to authentication during runtime, devices also need assurance that the software loaded is genuine each time the system starts up. Secure boot helps achieve this by verifying the integrity and validity of the operating system using cryptographic signatures. Technologies like Trusted Platform Module (TPM) can also securely store and protect the private keys used for authentication.
- Monitor for Anomalies
When embedded solution company are targeted by attackers, they often exhibit behaviors that differ from normal operations. Most intrusions will trigger anomalies in network traffic patterns, resource consumption or peripheral device activity that can act as warning signs. To detect such abnormalities early, embedded devices need active monitoring mechanisms.
The first step is to define baselines of what constitutes usual functioning – things like average network throughput, typical CPU and memory usage, standard input/output patterns. With this baseline established, the system can then monitor key parameters in real-time and flag any readings that deviate significantly. Techniques like behavioral analysis and log inspection are useful to spot anomalies. System call filtering can detect unauthorized changes to critical processes.
Specialized hardware like a hardware security module (HSM) or trusted execution environment (TEE) can also monitor firmware and software integrity in a tamper-proof manner. Any unauthorized modifications are promptly reported. By continuously tracking operational characteristics, deviations that could indicate an intrusion are caught quickly.
- Prepare for the Worst
Even with strong security practices, it is possible that vulnerabilities may be uncovered after a product is deployed. No system is completely impenetrable. Therefore, it is critical for embedded devices to have contingency plans in place in case of security incidents.
Organizations need to implement an incident response framework with clear guidelines on communication protocols, escalation procedures and remediation steps. Teams also require training through mock security drills to sharpen response skills. This ensures that in the event of an actual breach, the response will be swift and effective.
On the technical side, mechanisms like over-the-air firmware updates allow devices to quickly patch vulnerabilities remotely as soon as they are discovered. Critical data should also be isolated on removable media drives that can be easily wiped in an emergency. For mission-critical systems in industries like utilities, healthcare, etc., fail-safe controls must be designed to take over essential operations if the primary controllers fail due to attacks. This prevents disruptions to important services.
Following these five best practices of secure development, isolation, authentication, anomaly monitoring and incident preparation can help embedded systems achieve robust protection against evolving cyber threats. Outsourcing certain tasks like code reviews, security testing and pcb design service to specialized firms can also aid embedded product companies in proactively fortifying their systems through a defense-in-depth approach. Comprehensive security needs to be embedded by design.