The Quantum Threat: Why Industrial Control Systems Must Be Ready and How PQShield Is Leading the Defense

Industrial control systems (ICS) underpin the world’s most critical infrastructure: power grids, manufacturing plants, transportation networks, water systems, oil and gas facilities, and chemical processing operations. For decades, these systems relied on isolation, proprietary communication protocols, and hardware longevity as de facto security measures. But Industry 4.0, cloud integration, and the rapid expansion of industrial IoT have removed traditional boundaries, exposing ICS to a dramatically larger cyberattack surface. Now, an even bigger disruption looms: the coming era of quantum computing.

Quantum computers capable of running algorithms such as Shor’s threaten to break today’s public-key cryptography, specifically RSA and elliptic-curve cryptography. These algorithms currently secure authentication, firmware verification, remote connections, and confidential data flows across ICS and operational technology. Experts estimate that cryptographically relevant quantum computers may appear within the next decade, but adversaries do not need to wait. “Harvest-now, decrypt-later” attacks are already underway, where encrypted ICS traffic is collected today and stored for future decryption once quantum machines reach maturity. The long equipment lifespans common in industrial environments (often 10 to 30 years) often means many assets being deployed right now will still be in active use when quantum attacks become practical.

ICS environments face several unique challenges that make the quantum transition especially urgent. First, industrial devices are resource constrained. PLCs, RTUs, and embedded sensors often operate with limited memory and compute power, making it difficult to implement next-generation cryptographic algorithms without specialized optimization. Second, industrial networks have become deeply interconnected. The erosion of the once-reliable “air gap” exposes control-layer equipment to the same threats facing enterprise IT. Third, ICS operate in safety-critical environments where any compromise, whether firmware tampering, signal injection, or command spoofing, can have real-world physical consequences, from halted production to public safety hazards.

Governments and security agencies such as CISA, NIST, and ENISA have issued increasingly clear warnings: quantum computing will render today’s cryptography obsolete, and migration will be long, costly, and technically complex. For ICS operators, doing nothing is the riskiest option.

This is where PQShield has emerged as a global leader in practical, deployable post-quantum cryptography (PQC) for industrial systems. Founded in 2018 as a spin-out from the University of Oxford, PQShield has played a central role in the development, standardization, and commercialization of the PQC algorithms now selected by NIST: ML-KM (Kyber) for key establishment, ML-DSA for digital signatures, and SLH-DSA for hash-based signatures. As one of the few companies contributing to every stage of the NIST PQC process, PQShield brings unmatched cryptographic pedigree to the ICS market.

However, PQShield’s contribution extends beyond research. The company has built the industry’s most complete, production-ready PQC portfolio for embedded and constrained environments, the exact conditions found in ICS. PQShield’s PQMicroLib, for example, brings high-security PQC to microcontrollers with as little as ~13 kB RAM, making it a practical retrofit for brownfield industrial devices. For new greenfield deployments, PQShield provides side-channel-resistant hardware IP cores, quantum-secure boot, and firmware update mechanisms to protect the entire trust chain of industrial systems. Hybrid classical-plus-PQC libraries support gradual migration, maintaining compatibility with existing infrastructure while building quantum resilience.

PQShield is also deeply active in ICS-relevant standards bodies, including the Industrial Internet Consortium (IIC) and ISA/IEC 62443 working groups. Its customers span semiconductor manufacturers, automotive suppliers, energy operators, and defense organizations—sectors where security and long-term reliability are paramount.

To prepare for the quantum era, ICS operators should start by conducting a full cryptographic inventory, identifying where vulnerable algorithms are used in authentication, key exchange, VPNs, and firmware verification. Next, organizations should adopt NIST-standard PQC algorithms and prioritize quantum-resistant secure boot and OTA update mechanisms. Finally, they should work with specialized partners, such as PQShield, to develop crypto-agility strategies and ensure both new and legacy systems can be upgraded over time.

Bottom line: The quantum threat is real, inevitable, and approaching fast. Organizations that move early will avoid expensive, last-minute retrofits and significantly reduce operational risk. With companies like PQShield providing the tools, standards alignment, and engineering depth needed to secure industrial systems, the path to quantum-safe ICS is now both achievable and urgent.

Contact PQShield

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Formal Verification: Why It Matters for Post-Quantum Cryptography