Building Trust in Embedded Systems: Securing the Software Supply Chain

Why Supply Chain Security Matters More Than Ever

Modern embedded systems are no longer isolated circuits with static firmware. They’re connected, updateable, and often integrate third-party software — from open-source libraries to AI models.
This complexity makes them both powerful and vulnerable.

Recent years have seen a surge in supply chain attacks that compromise devices before they even reach customers — through manipulated firmware, infected build tools, or compromised dependencies.

For embedded developers, this marks a major shift in priorities. It’s not enough to secure communication or data; now, the entire development and delivery pipeline must be protected.

This is where key practices like SBOM (Software Bill of Materials), Secure Boot, and compliance with the Cyber Resilience Act (CRA) come into play. Together, they form the foundation of a trustworthy embedded software ecosystem.

Understanding the Embedded Software Supply Chain

A typical embedded product’s software stack is far from simple. It might include:
– The bootloader and firmware base.
– Real-time operating system (RTOS) or embedded Linux.
– Middleware, protocol stacks, and security libraries.
– Third-party drivers, open-source code, or even AI inference engines.

Every external component added to this stack introduces a potential vulnerability. A single outdated library or unverified dependency can expose the device to exploits or non-compliance.

Supply chain security, therefore, isn’t just about encryption or antivirus measures — it’s about visibility and integrity across the entire lifecycle, from code sourcing to firmware updates in the field.

The Rise of SBOM: Visibility as the First Line of Defense

The Software Bill of Materials (SBOM) is a detailed inventory of every software component in a product — including its version, origin, and dependencies.

In embedded systems, it serves as both a transparency tool and a compliance requirement.

By knowing exactly what’s inside the firmware, developers can:

1. Identify outdated or vulnerable components faster.
    
2. Manage open-source license obligations.
    
3. Simplify security audits and certifications.
    
4. Respond quickly to CVEs (Common Vulnerabilities and Exposures).
    

For OEMs managing hundreds of firmware versions across products, SBOMs are becoming an operational necessity.

Standards such as SPDX, CycloneDX, and SWID are already widely supported by security platforms and build tools, allowing automated generation and integration into CI/CD pipelines.

In the context of CRA and future EU regulations, SBOMs will likely be mandatory — especially for connected devices and industrial control systems.

Secure Boot: The Foundation of Firmware Trust

If SBOM answers what’s inside the firmware, Secure Boot answers is this firmware authentic?

Secure Boot ensures that only verified and cryptographically signed code can execute on the device. The mechanism prevents attackers from injecting malicious or unauthorized firmware — whether during production, distribution, or updates.

Here’s how it works conceptually:
– The bootloader contains a public key burned into read-only memory.
– When the device starts, it verifies the digital signature of the next stage (firmware image).
– Only if the signature matches does the system continue the boot process.

This chain of trust can extend through multiple layers: bootloader → OS kernel → user applications → over-the-air updates.

In industries like automotive, aerospace, and industrial control, Secure Boot has become a baseline requirement, often combined with hardware root of trust (HRoT) solutions such as TPM, TrustZone, or custom secure elements.

The challenge for many companies is ensuring key management, manufacturing integration, and update flexibility without compromising the chain of trust.

The Cyber Resilience Act (CRA) and Its Impact on Embedded Devices

The EU Cyber Resilience Act, expected to reshape product compliance across Europe, represents one of the most significant regulatory shifts for embedded developers in years.

It mandates that all products with digital elements — from consumer IoT devices to industrial controllers — meet security-by-design principles and maintain ongoing security updates throughout their lifecycle.

Key obligations include:

1. Security risk management. Manufacturers must assess and mitigate risks before product release.
    
2. Vulnerability handling. Developers must monitor, report, and fix security issues promptly.
    
3. Transparency. Users and authorities should know what software is included (through SBOMs).
    
4. Incident reporting. Breaches must be disclosed within a fixed timeframe.
    

Failure to comply can lead to product recalls or market bans — not just fines.

For embedded companies selling into the EU, aligning design and documentation practices with CRA is no longer optional; it’s a survival requirement.

Linking SBOM, Secure Boot, and CRA Together

These three components — SBOM, Secure Boot, and CRA — are deeply interconnected:

– SBOM ensures visibility: you know what your firmware includes.
– Secure Boot ensures integrity: you know it hasn’t been tampered with.
– CRA compliance ensures accountability: you follow structured processes for security and updates.

Together, they close the loop between transparency, authenticity, and responsibility.

Implementing them consistently helps companies transition from reactive patching to proactive resilience — reducing long-term risk and improving trust with regulators and customers.

Threat Landscape for Embedded Supply Chains

Embedded systems face unique threats that traditional IT infrastructure often overlooks:

– Firmware tampering during contract manufacturing.
– Malicious updates over insecure OTA pipelines.
– Compromised third-party drivers embedded deep in SDKs.
– Counterfeit components with pre-flashed malware.
– Stolen signing keys used to distribute fake firmware.

Because many devices operate in remote or inaccessible locations, detecting and mitigating these threats can take months. Building a secure chain of trust into every phase — from design to decommissioning — becomes essential.

Practical Steps for Developers

1. Integrate SBOM generation early. Automate SBOM creation as part of every build. Keep version history aligned with releases.
    
2. Adopt signed firmware updates. Use asymmetric cryptography and validated OTA frameworks.
    
3. Secure the toolchain. Protect compilers, version control systems, and CI/CD pipelines against tampering.
    
4. Implement hardware root of trust. Embed cryptographic keys in secure hardware and enforce immutable boot sequences.
    
5. Perform dependency scanning. Regularly check open-source and vendor components against CVE databases.
    
6. Document everything. CRA compliance relies on demonstrable processes, not just technical features.
    

These measures might seem like overhead, but they dramatically reduce the probability and cost of a future incident.

The Role of Hardware Vendors and Integrators

Chip vendors and EMS providers also play a crucial part in supply chain security. They are responsible for secure provisioning, firmware flashing, and ensuring that cryptographic keys remain protected during manufacturing.

Integrators should establish trusted provisioning pipelines, often with vendor-backed platforms such as secure manufacturing services or key injection facilities.

For OEMs outsourcing production, contractual clauses must define responsibility for key handling, logging, and tamper detection.

In short — no part of the chain should be trusted by default; every link must verify the one before it.

Balancing Security, Cost, and Time-to-Market

Security comes with engineering trade-offs. Stronger protection means longer validation, more documentation, and potential hardware overhead.

The key is balance:
– For high-volume consumer products, focus on automated SBOM and OTA signing systems.
– For industrial or automotive devices, add dedicated secure elements and lifecycle monitoring.
– For niche or safety-critical systems, include tamper detection and hardware isolation.

What’s changing is perception — security is no longer an afterthought but a design parameter with measurable ROI.

A secure supply chain prevents recalls, reduces warranty costs, and builds brand reputation — all quantifiable business outcomes.

Real-World Examples and Industry Momentum

Automotive:
Tier-1 suppliers are aligning with ISO/SAE 21434 and CRA by introducing mandatory SBOM reporting. Secure Boot and firmware signing are now standard across most ECUs.

Medical Devices:
Manufacturers are required under EU MDR and FDA guidance to provide SBOMs and ensure update mechanisms that preserve patient safety.

Industrial IoT:
Vendors are implementing Secure Boot via TPMs and embedded HSMs to protect PLCs and gateways from firmware manipulation.

Consumer Electronics:
Companies like Samsung and LG already integrate Secure Boot and remote attestation to meet upcoming CRA readiness requirements.

This cross-industry alignment means best practices are quickly converging — a clear sign that compliance and security are becoming inseparable.

Looking Ahead: Toward Self-Healing Supply Chains

Future embedded systems will go beyond static verification. They’ll continuously monitor integrity through runtime attestation, firmware provenance tracking, and even AI-driven anomaly detection during updates.

The goal is a self-healing supply chain — where every component can verify its origin, authenticity, and operational state autonomously.

Emerging standards like Uptane (for secure updates) and in-tandem SBOM validation across connected networks are paving the way.

As CRA enforcement tightens, these technologies will likely become part of standard compliance toolkits.

Why Now Is the Right Time to Act

Regulations are accelerating, customers are becoming more security-aware, and attackers are targeting firmware like never before.

Companies that implement SBOMs, Secure Boot, and CRA-aligned processes now gain a major competitive advantage: faster certification, better customer trust, and smoother scaling into regulated markets.

In the embedded world, trust isn’t declared — it’s engineered.

AI Overview

Key Applications: secure firmware development, embedded software lifecycle protection, manufacturing security, OTA integrity, and CRA compliance for connected devices.
Benefits: full visibility into software components (SBOM), tamper-proof boot processes, proactive regulatory compliance, and improved product trust.
Challenges: managing cryptographic keys, securing supply chain partners, integrating compliance documentation, and maintaining agility under regulation.
Outlook: As the EU Cyber Resilience Act takes effect, SBOMs and Secure Boot will become mandatory for embedded products, transforming security from an add-on into a core design discipline.
Related Terms: hardware root of trust, OTA signing, SPDX, CycloneDX, firmware attestation, supply chain transparency, embedded compliance.