This chapter provides practical guidance for replacing cryptographic algorithms vulnerable to quantum attacks, such as RSA, ECC, and Diffie-Hellman, with quantum-resistant alternatives approved or shortlisted by NIST. It explores transition strategies, including direct replacement with algorithms like ML-KEM, Dilithium, and Falcon, and hybrid deployment models that combine classical and quantum-safe algorithms for backward compatibility. Readers are introduced to deployment options within TLS 1.3, VPNs, code signing, authentication, and other cryptographic workflows, with references to relevant standards such as RFC 8784 (hybrid key exchange in IKEv2), RFC 9242 (hybrid authentication in TLS 1.3), and RFC 9370 (quantum-safe IPsec). The chapter discusses the complexity of implementing algorithm replacements in distributed environments, especially where legacy systems, hardware security modules (HSMs), and constrained devices introduce friction. It provides examples of dual-stack certificate usage and phased cutovers to help organizations minimize service disruption. Special attention is given to vendor compatibility, cryptographic agility, and open-source tools such as OpenSSL, BoringSSL, and liboqs, which are essential for pilot deployments and evaluation. Practical testing, fallback planning, and rollback strategies are included to manage risk during transition. K eywords : post-quantum cryptography (PQC), ML-KEM, CRYSTALS-Dilithium, Falcon, RSA deprecation, ECC replacement, hybrid certificates, dual-stack architecture, cryptographic algorithm migration, RFC 8784, RFC 9242, RFC 9370, TLS 1.3, quantum-safe VPN, IPsec, IKEv2, PQC libraries, OpenSSL, BoringSSL, liboqs, HSM compatibility, cryptographic agility, secure key exchange, post-quantum standards, interoperability testing.This chapter provides practical guidance for replacing cryptographic algorithms vulnerable to quantum attacks, such as RSA, ECC, and Diffie-Hellman, with quantum-resistant alternatives approved or shortlisted by NIST. It explores transition strategies, including direct replacement with algorithms like ML-KEM, Dilithium, and Falcon, and hybrid deployment models that combine classical and quantum-safe algorithms for backward compatibility. Readers are introduced to deployment options within TLS 1.3, VPNs, code signing, authentication, and other cryptographic workflows, with references to relevant standards such as RFC 8784 (hybrid key exchange in IKEv2), RFC 9242 (hybrid authentication in TLS 1.3), and RFC 9370 (quantum-safe IPsec). The chapter discusses the complexity of implementing algorithm replacements in distributed environments, especially where legacy systems, hardware security modules (HSMs), and constrained devices introduce friction. It provides examples of dual-stack certificate usage and phased cutovers to help organizations minimize service disruption. Special attention is given to vendor compatibility, cryptographic agility, and open-source tools such as OpenSSL, BoringSSL, and liboqs, which are essential for pilot deployments and evaluation. Practical testing, fallback planning, and rollback strategies are included to manage risk during transition. K eywords : post-quantum cryptography (PQC), ML-KEM, CRYSTALS-Dilithium, Falcon, RSA deprecation, ECC replacement, hybrid certificates, dual-stack architecture, cryptographic algorithm migration, RFC 8784, RFC 9242, RFC 9370, TLS 1.3, quantum-safe VPN, IPsec, IKEv2, PQC libraries, OpenSSL, BoringSSL, liboqs, HSM compatibility, cryptographic agility, secure key exchange, post-quantum standards, interoperability testing.

CRC Press eBooksDec 12, 20250 citations

Quantum Safe Networks: A Case Study on Securing QKD Interfaces Using PQC

Sayan Das, Aarav Varshney, Prasanna Ravi +1 more

Quantum-Safe Networks (QSNs) use quantum key distribution (QKD) to deliver keys generated using a Quantum Random Number Generator (QRNG) to consumers at scale. In practice, prevailing Quantum-Key-as-a-Service (QKaaS) offerings still assume that each consumer site deploys on-premise QKD hardware, creating cost and feasibility barriers that limit adoption. Although ETSI GS QKD 014 standardizes APIs for key retrieval between Secure Application Entities (SAEs) and Key Management Entities (KMEs), it does not address key delivery across untrusted classical networks to consumers without local QKD devices. We close this gap with a gateway architecture that transparently secures ETSI-compliant QKD APIs using Post-Quantum Cryptography (PQC)—applying PQC signatures and key-encapsulation mechanisms end-to-end—without requiring changes to existing devices or software. The design supports cryptographic agility, enabling runtime selection and rotation among standardized PQC schemes. Evaluations on both simulated QKD environments and production-grade hardware show minimal overhead ( $\approx 1.3\times$ –1.5× versus baseline) and robust scaling across concurrent connections and multiple consumer sites, extending the reach of QSNs beyond premises equipped with QKD while preserving end-to-end quantum-safe guarantees. Overall, this paper equips practitioners with a systematized view of PQC–QKD integration in QSNs, with an actionable gateway blueprint for extending QSNs without the need for on-premise QKD deployments.Quantum-Safe Networks (QSNs) use quantum key distribution (QKD) to deliver keys generated using a Quantum Random Number Generator (QRNG) to consumers at scale. In practice, prevailing Quantum-Key-as-a-Service (QKaaS) offerings still assume that each consumer site deploys on-premise QKD hardware, creating cost and feasibility barriers that limit adoption. Although ETSI GS QKD 014 standardizes APIs for key retrieval between Secure Application Entities (SAEs) and Key Management Entities (KMEs), it does not address key delivery across untrusted classical networks to consumers without local QKD devices. We close this gap with a gateway architecture that transparently secures ETSI-compliant QKD APIs using Post-Quantum Cryptography (PQC)—applying PQC signatures and key-encapsulation mechanisms end-to-end—without requiring changes to existing devices or software. The design supports cryptographic agility, enabling runtime selection and rotation among standardized PQC schemes. Evaluations on both simulated QKD environments and production-grade hardware show minimal overhead ($\approx 1.3\times$–1.5× versus baseline) and robust scaling across concurrent connections and multiple consumer sites, extending the reach of QSNs beyond premises equipped with QKD while preserving end-to-end quantum-safe guarantees. Overall, this paper equips practitioners with a systematized view of PQC–QKD integration in QSNs, with an actionable gateway blueprint for extending QSNs without the need for on-premise QKD deployments.

IEEE Transactions on Network Science and EngineeringJan 1, 20260 citations

Toward a Quantum-Safe Communication Infrastructure

NATO science for peace and security series. D, Information and communication securityFeb 19, 20240 citations

Mind the Gap: Policy vs Reality in Post-Quantum TLS Deployment

Nimesha Wickramasinghe, Frank Li, Sanjay Jha +1 more

Post-quantum cryptography (PQC) has evolved from a long-term planning concern into an operational priority. Following NIST's standardization of PQC algorithms, governments and standards bodies published transition roadmaps outlining migration timelines, priority sectors, and deployment strategies. However, our survey of these policies reveals substantial divergence in technical prescriptions and urgency. It remains unclear how widely PQC has been adopted in practice and how policy differences translate into observable deployment outcomes.Post-quantum cryptography (PQC) has evolved from a long-term planning concern into an operational priority. Following NIST's standardization of PQC algorithms, governments and standards bodies published transition roadmaps outlining migration timelines, priority sectors, and deployment strategies. However, our survey of these policies reveals substantial divergence in technical prescriptions and urgency. It remains unclear how widely PQC has been adopted in practice and how policy differences translate into observable deployment outcomes.

arXiv:2607.29005ACM Internet Measurement Conference (IMC)Sep 29, 20260 citations

Toward Quantum-Safe Migration: Benchmarking NIST PQC on Modern ARM Architectures

Muhamad Akrom, Supriadi Rustad, Guruh Fajar Shidik +3 more

Optics CommunicationsOct 1, 20260 citations

\approx 1.3\times

–1.5× versus baseline) and robust scaling across concurrent connections and multiple consumer sites, extending the reach of QSNs beyond premises equipped with QKD while preserving end-to-end quantum-safe guarantees. Overall, this paper equips practitioners with a systematized view of PQC–QKD integration in QSNs, with an actionable gateway blueprint for extending QSNs without the need for on-premise QKD deployments.