Post-Quantum Cryptography: Securing Embedded Systems for the Next Era

Quantum computing has moved from theory to labs and early prototypes, and its progress creates a very real challenge: most of today’s encryption methods won’t hold up once quantum computers become powerful enough. For embedded systems — the small, specialized devices running cars, telecom networks, medical devices, and industrial controls — this isn’t just a distant worry. These systems often live in the field for decades, meaning they may face quantum-enabled attacks within their lifetimes.

That’s why post-quantum cryptography (PQC) has become one of the hottest topics in embedded security. It promises to bring new algorithmic approaches that are resistant to quantum attacks, ensuring devices can stay safe even in a future where quantum computing is widely available.

Why quantum computers threaten today’s encryption

Modern encryption relies on the difficulty of solving certain mathematical problems. RSA and ECC (Elliptic Curve Cryptography), for instance, depend on factoring large numbers or solving discrete logarithms. These are nearly impossible for classical computers, but quantum computers running Shor’s algorithm could crack them much faster.

For consumer apps, this might mean a need to patch software. For embedded systems, though, patching isn’t always easy — especially for devices deployed in cars, power grids, or telecom backbones. That’s why engineers are already preparing for a transition to quantum-safe security.

What post-quantum cryptography means for embedded devices

Post-quantum cryptography doesn’t rely on problems vulnerable to quantum algorithms. Instead, it uses new families of math, such as lattice-based, hash-based, multivariate polynomial, and code-based cryptography. These have been under review by NIST (the U.S. National Institute of Standards and Technology), which is in the process of standardizing PQC algorithms.

For embedded engineers, the implications are huge:

• Hardware upgrades: Many current MCUs and SoCs weren’t designed to handle the larger key sizes and higher computational demands of PQC. This means future embedded chips may need hardware acceleration for PQC operations.
• Firmware integration: Device firmware will need updates to integrate quantum-safe protocols while maintaining backward compatibility with legacy systems.
• Secure boot and OTA updates: Secure boot processes must evolve to PQC, ensuring that only trusted firmware runs on embedded devices. Over-the-air updates will also need to use quantum-resistant keys.

Industry examples and use cases

Let’s take a look at where PQC is already becoming a focus:

• Automotive: Modern cars rely on connected ECUs, over-the-air updates, and V2X communication. PQC will be essential for ensuring these updates and vehicle-to-vehicle links can’t be spoofed in a quantum era.
• Telecom: Routers, switches, and 5G base stations form critical infrastructure. Their long lifecycle makes them prime candidates for PQC migration to keep networks secure.
• Medical devices: Pacemakers and connected imaging equipment require strong data protection. Since patient safety is at stake, PQC is becoming a must-have in new device design.
• Industrial IoT: Factories and energy systems rely on embedded sensors and controllers. PQC will prevent malicious actors from injecting false data or taking over systems when quantum attacks become viable.

Real-world adoption is starting

In 2024, NIST selected its first round of PQC algorithms, including CRYSTALS-Kyber for key encapsulation and CRYSTALS-Dilithium for digital signatures. Hardware vendors such as Intel and NXP have already begun integrating support for these algorithms into their roadmaps.

For embedded developers, this means PQC is no longer just a research project. It’s time to start prototyping and testing how these algorithms fit into constrained environments. Some startups are even building lightweight PQC libraries optimized for low-power MCUs, showing that adoption is possible without massive hardware changes.

Long-tail questions developers ask

• When should embedded systems adopt PQC?
  Ideally during the design phase of new products, especially those expected to operate beyond 2030. Retrofitting old devices will be much harder.
• Will PQC slow down performance on embedded devices?
  Some algorithms do require more processing power, but hardware acceleration and optimized libraries are making performance trade-offs manageable.
• How can companies prepare today?
  By testing hybrid systems that support both classical and quantum-safe algorithms, ensuring a smooth migration path.

Looking ahead

Quantum computing is advancing fast, and while no one can predict the exact year when it will outpace classical cryptography, the timeline could fall within the lifecycle of many embedded products being designed today. That makes PQC not just a future concern but a present design requirement.

Engineers, product managers, and system architects working in automotive, industrial, medical, and telecom sectors should see PQC as part of their long-term security roadmap. The transition will not happen overnight, but those who prepare early will save enormous costs and risks later.

The next era of embedded security will be defined not by reacting to quantum threats once they arrive, but by building quantum-resistant systems today.