While the current progress in quantum computing opens new opportunities in a wide range of scientific fields, it poses a serious threat to today?s asymmetric cryptography. New quantum resistant primitives are already available but under active investigation. To avoid the risk of deploying immature schemes we combine them with well-established classical primitives to hybrid schemes, thus hedging our bets. Because quantum resistant primitives have higher resource requirements, the transition to them will affect resource constrained IoT devices in particular. We propose two modifications for the authenticated key establishment process of the industrial machine-to-machine communication protocol OPC UA to make it quantum resistant. Our first variant is based on Kyber for the establishment of shared secrets and uses either Falcon or Dilithium for digital signatures in combination with classical RSA. The second variant is solely based on Kyber in combination with classical RSA. We modify existing opensource software (open62541, mbedTLS) to integrate our two proposed variants and perform various performance measurements
While the current progress in quantum computing opens new opportunities in a wide range of scientific fields, it poses a serious threat to today?s asymmetric cryptography. New quantum resistant primitives are already available but under active investigation. To avoid the risk of deploying immature schemes we combine them with well-established classical primitives to hybrid schemes, thus hedging our bets. Because quantum resistant primitives have higher resource requirements, the transition to them will affect resource constrained IoT devices in particular. We propose two modifications for the authenticated key establishment process of the industrial machine-to-machine communication protocol OPC UA to make it quantum resistant. Our first variant is based on Kyber for the establishment of shared secrets and uses either Falcon or Dilithium for digital signatures in combination with classical RSA. The second variant is solely based on Kyber in combination with classical RSA. We modify existing opensource software (open62541, mbedTLS) to integrate our two proposed variants and perform various performance measurements
The threat of a cryptographically relevant quantum computer contributes to an increasing interest in the field of post-quantum cryptography (PQC). Compared to existing research efforts regarding the integration of PQC into the Transport Layer Security (TLS) protocol, industrial communication protocols have so far been neglected. Since industrial cyber-physical systems (CPS) are typically deployed for decades, protection against such long-term threats is needed. In this work, we propose two novel solutions for the integration of post-quantum (PQ) primitives (digital signatures and key establishment) into the industrial protocol Open Platform Communications Unified Architecture (OPC UA): a hybrid solution combining conventional cryptography with PQC and a solution solely based on PQC. Both approaches provide mutual authentication between client and server and are realized with certificates fully compliant to the X.509 standard. We implement the two solutions and measure and evaluate their performance across three different security levels. All selected algorithms (Kyber, Dilithium, and Falcon) are candidates for standardization by the National Institute of Standards and Technology (NIST). We show that Falcon is a suitable option – especially – when using floating-point hardware provided by our ARM-based evaluation platform. Our proposed hybrid solution provides PQ security for early adopters but comes with additional performance and communication requirements. Our solution solely based on PQC shows superior performance across all evaluated security levels in terms of handshake duration compared to conventional OPC UA but comes at the cost of increased handshake sizes. In addition to our performance evaluation, we provide a proof of security in the symbolic model for our two PQC-based variants of OPC UA. For this proof, we use the cryptographic protocol verifier ProVerif and formally verify confidentiality and authentication properties of our quantum-resistant variants.
Cyber-physical systems (CPS) are considered a crucial part for providing connectivity in industrial environments. However, the recent increase in connectivity has led to an extended attack vector. Therefore, it is important that CPS are secured against current and - due to their long life span - also against future threats, such as quantum computers. The security of present communication can be broken once a sufficiently powerful quantum computer is available. To protect against this attack vector, applications and protocols should start utilizing quantum-resistant primitives. One approach that maintains common security guarantees and protects against quantum computer attacks is to use hybrid constructions: a combination of classically secure and quantum-resistant schemes. In this work, we propose a hybrid key exchange mechanism for the industrial communication protocol Open Platform Communications Unified Architecture (OPC UA). We describe four distinct instantiations based on selected quantum-resistant key encapsulation mechanisms (KEMs), namely NewHope, NTRU, CRYSTALS-Kyber, and Saber. We implement our resulting quantum-resistant modifications of OPC UA on two different ARM based platforms and present detailed performance footprints. Finally, we show the feasibility of employing hybrid quantum-resistant key exchange within OPC UA preserving industrial communication against future threats.
The growing interconnection of critical engineering infrastructure through IoT introduces unprecedented exposure to cyber threats. Emerging quantum computing capabilities pose a transformative risk to classical cryptographic primitives such as Rivest–Shamir–Adleman and Elliptic-Curve Cryptography, which underpin secure communication and device authentication in industrial control systems, power grids, transportation networks, and healthcare infrastructure. This paper investigates quantum-resistant encryption, often termed post-quantum cryptography (PQC), as a sustainable security paradigm for IoT communication within critical systems. By analyzing lattice-based, code-based, multivariate, and hash-based schemes, the study evaluates trade-offs between computational cost, memory footprint, and latency constraints intrinsic to resource-limited IoT nodes. A hybrid architectural framework integrating the National Institute of Standards and Technology-standardized algorithms (e.g., Cryptographic Suite for Algebraic Lattices—Kyber, Dilithium) with lightweight symmetric primitives (e.g., Ascon, GIFT block cipher in Combined Feedback mode) is proposed for secure data transmission across heterogeneous IoT layers. Experimental simulations benchmark key-exchange throughput, ciphertext expansion, and resilience against quantum-adversarial models, demonstrating up to 65% reduction in handshake latency compared to baseline lattice implementations under constrained conditions. The paper concludes with policy and engineering recommendations for the adoption of quantum-resistant IoT protocols in energy, transportation, and industrial automation sectors, highlighting alignment with global PQC migration roadmaps and IEC 62443 cybersecurity standards.
The rise of quantum computers threatens the security of current TLS protocols, which rely on elliptic curve and RSA-based primitives that quantum algorithms like Shor's can break. This creates a “store now, decrypt later” risk, where attackers may collect encrypted data today to decrypt it in the future once quantum capabilities advance. This study introduces a novel hybrid TLS protocol that seamlessly integrates classical (ECDSA and X25519) and post-quantum (CRYSTALS-Dilithium5 and CRYSTALS-Kyber1024) primitives. The proposed method generates a composite X. 509 certificate dual-signed with ECDSA and Dilithium5. It conducts a key exchange that concatenates an X25519 Diffie-Hellman shared secret with a Kyber KEM shared secret, followed by HKDF-SHA256 key derivation. The entire protocol is implemented in Go, leveraging the OQS liboqs-go library alongside Go's standard crypto packages. Experimental validation via a proof-of-concept demonstrates successful hybrid certificate validation and secure session establishment with both classical and post-quantum peers. These results confirm that hybrid cryptographic integration can provide quantum-resilient security while preserving compatibility with existing TLS deployments.
The rapid expansion of Internet of Things (IoT) ecosystems has increased the need for communication mechanisms that can remain secure against emerging computational threats. Conventional asymmetric cryptographic schemes, including RSA and Elliptic Curve Cryptography (ECC), are vulnerable to advances in quantum computing due to the ability of Shor's algorithm to undermine their underlying mathematical assumptions. To address these challenges, this paper presents PQ-IoT SecureCom, a quantum-resistant communication framework built using NIST-standardized post-quantum cryptographic primitives. The proposed framework employs ML-KEM (derived from Kyber) for secure key encapsulation and ML-DSA (derived from Dilithium) for digital authentication, combined with AESGCM to ensure data confidentiality and integrity. Additional security mechanisms, including PQC-based device certification, periodic session key updates, and nonce-based timestamp validation, are incorporated to mitigate replay and impersonation attacks. The framework also supports a hybrid operational mode that enables performance comparison between classical and postquantum cryptographic schemes. System behavior is monitored using a real-time dashboard that records cryptographic overhead, communication metrics, and detected security events. Experimental evaluation shows that ML-KEM and ML-DSA significantly enhance security while introducing computational overhead that remains acceptable for contemporary IoT devices. Through automated attack simulations and detailed event logging, PQ-IoT SecureCom demonstrates the practical feasibility of deploying scalable post-quantum security in IoT communication systems.
The fast development of quantum computing presents a great threat to the security of classical cryptographic algorithms that support secure communication systems like Virtual Private Networks (VPNs). RSA and ECC algorithms that are commonly employed in key exchange and digital authentication can fall victim to quantum attacks from Shor’s and Grover’s algorithms. This study introduces the design and deployment of a post-quantum-resistant VPN protocol using post-quantum cryptographic (PQC) primitives, i.e., Kyber for key encapsulation and Dilithium for digital signatures. The suggested structure is incorporated into OpenVPN via the Open Quantum Safe (OQS) framework for uninterrupted post-quantum compatibility. The protocol is also capable of supporting hybrid cryptography for smooth transition from classical to post-quantum systems. Performance benchmarks are performed over metrics like handshake latency, tunnel throughput, CPU usage, and certificate overhead. The findings illustrate that post-quantum secure VPNs are not only achievable but also feasible for near-future deployment. This work adds a future-proof framework to improve the resilience of secure communications in the post-quantum era with a focus on scalability, crypto-agility, and real-world implementation readiness.