Shor’s algorithm efficiently solves factoring and discrete logarithm problems using quantum computers, compromising all public key schemes used today. Algorithms such as RSA, DHKE, and ECC will not work in a world with quantum computers, since they can easily invert the functions that provide their computational strength in the classical world. These schemes rely on assumptions on their computational complexity, which quantum computers can easily bypass. The solutions have to come from new algorithms – called Post-Quantum Cryptography (PQC) – or from new methods, such as Quantum Key Distribution (QKD). The former replicate the computational security ideas of classical public key algorithms, while the latter recurs to use the quantum properties of nature, which also brings a mathematical security proof, potentially offering Information-Theoretic Security. To secure data in the future, we must adopt these paradigms. With the speed of quantum computing advancements, the transition to quantum-safe cryptography within the next decade is critical. Delays could expose long-lived confidential data, as current encryption may be broken before its value expires. However, the shift must balance the adoption of new technologies with maintaining proven systems to protect against present and future threats. In this work, we have selected Transport Layer Security (TLS), one of the most widely used protocols, as the foundation to hybridize classical, quantum, and post-quantum cryptography in a way suitable for broad adoption in Software-Defined Networking (SDN), the most flexible networking paradigm that has been used to deploy integrated quantum–classical networks. To this end, we use standards for QKD key extraction and SDN integration. The purposed implementation is based on the latest version of TLS (1.3) and demonstrates advanced capabilities such as rekeying and key transport across a large QKD network, while supporting crypto-agility and maintaining backward compatibility through the use of ciphersuites. The performance of this approach has been demonstrated using a deployed production infrastructure.
Shor’s algorithm efficiently solves factoring and discrete logarithm problems using quantum computers, compromising all public key schemes used today. Algorithms such as RSA, DHKE, and ECC will not work in a world with quantum computers, since they can easily invert the functions that provide their computational strength in the classical world. These schemes rely on assumptions on their computational complexity, which quantum computers can easily bypass. The solutions have to come from new algorithms – called Post-Quantum Cryptography (PQC) – or from new methods, such as Quantum Key Distribution (QKD). The former replicate the computational security ideas of classical public key algorithms, while the latter recurs to use the quantum properties of nature, which also brings a mathematical security proof, potentially offering Information-Theoretic Security. To secure data in the future, we must adopt these paradigms. With the speed of quantum computing advancements, the transition to quantum-safe cryptography within the next decade is critical. Delays could expose long-lived confidential data, as current encryption may be broken before its value expires. However, the shift must balance the adoption of new technologies with maintaining proven systems to protect against present and future threats. In this work, we have selected Transport Layer Security (TLS), one of the most widely used protocols, as the foundation to hybridize classical, quantum, and post-quantum cryptography in a way suitable for broad adoption in Software-Defined Networking (SDN), the most flexible networking paradigm that has been used to deploy integrated quantum–classical networks. To this end, we use standards for QKD key extraction and SDN integration. The purposed implementation is based on the latest version of TLS (1.3) and demonstrates advanced capabilities such as rekeying and key transport across a large QKD network, while supporting crypto-agility and maintaining backward compatibility through the use of ciphersuites. The performance of this approach has been demonstrated using a deployed production infrastructure.
Shor's algorithm efficiently solves factoring and discrete logarithm problems using quantum computers, compromising all public key schemes used today. These schemes rely on assumptions on their computational complexity, which quantum computers can easily bypass. The solutions have to come from new algorithms - called Post-Quantum Cryptography (PQC) - or from new methods, such as Quantum Key Distribution (QKD). The former replicate the computational security ideas of classical public key algorithms, while the latter recurs to use the quantum properties of nature, which also brings a mathematical security proof, potentially offering Information-Theoretic Security. To secure data in the future, we must adopt these paradigms. With the speed of quantum computing advancements, the transition to quantum-safe cryptography within the next decade is critical. Delays could expose long-lived confidential data, as current encryption may be broken before its value expires. However, the shift must balance the adoption of new technologies with maintaining proven systems to protect against present and future threats. In this work, we have selected Transport Layer Security, one of the most widely used protocols, as the foundation to hybridize classical, quantum, and post-quantum cryptography in a way suitable for broad adoption in Software-Defined Networking, the most flexible networking paradigm that has been used to deploy integrated quantum-classical networks. To this end, we use standards for QKD key extraction and SDN integration. The purposed implementation is based on the latest version of TLS and demonstrates advanced capabilities such as rekeying and key transport across a large QKD network, while supporting crypto-agility and maintaining backward compatibility through the use of ciphersuites. The performance of this approach has been demonstrated using a deployed production infrastructure.
Advances in quantum computing pose a significant threat to the widely used Public Key Infrastructure (PKI). The two leading technologies to address this challenge are Post-Quantum Cryptography and Quantum Key Distribution. A promising approach is the hybridization of these technologies - combining their respective strengths while mitigating their limitations - and integrating them with the cryptographic mechanisms used today to enhance crypto-agility and facilitate transitioning to a quantum-safe infrastructure. However, changing current network protocols to quantum-safe alternatives is not just a matter of security: their efficiency and scalability must also be demonstrated within real-world telecommunications infrastructures to ensure their practical adoption. In this work, we present the first long-running test with detailed measurements of a suite of hybrid quantum-safe protocols that integrate classical cryptography, PQC, and QKD within a production environment (MadQCI). Using standardized protocols and interfaces and employing Transport Layer Security (TLS) as the base protocol for real-world comparison, this study demonstrates the efficiency and scalability of the proposed solution in deployed heterogeneous networks. These results mark a significant step towards the widespread adoption of quantum-safe hybrid protocols and contribute to clarifying the path toward their future standardization in next-generation telecommunications networks.
Abstract Advances in quantum computing pose a significant threat to the widely used Public Key Infrastructure (PKI). The two leading technologies to address this challenge are Post-Quantum Cryptography and Quantum Key Distribution. A promising approach is the hybridization of these technologies - combining their respective strengths while mitigating their limitations - and integrating them with the cryptographic mechanisms used today to enhance crypto-agility and facilitate transitioning to a quantum-safe infrastructure. However, changing current network protocols to quantum-safe alternatives is not just a matter of security: their efficiency and scalability must also be demonstrated within real-world telecommunications infrastructures to ensure their practical adoption. In this work, we present the first long-running test with detailed measurements of a suite of hybrid quantum-safe protocols that integrate classical cryptography, PQC, and QKD within a production environment (MadQCI). Using standardized protocols and interfaces and employing Transport Layer Security (TLS) as the base protocol for real-world comparison, this study demonstrates the efficiency and scalability of the proposed solution in deployed heterogeneous networks. These results mark a significant step towards the widespread adoption of quantum-safe hybrid protocols and contribute to clarifying the path toward their future standardization in next-generation telecommunications networks.
The threats are existential to the traditional cryptosystems of public keys, including RSA, Diffie-Hellman, and elliptic curve cryptography (ECC), due to the rapid progress in quantum computing. Such algorithms as the Shor and Grover algorithms prove that as soon as large scale quantum computers are achieved, these classical cryptographic protocols will not provide any privacy and integrity to online communication. This has created an emergency to find post-quantum cryptography (PQC), or quantum-safe cryptography, which will resist attacks by both classical and quantum attackers. The paper is a review of the latest research and development in post-quantum cryptographic algorithms and their implementation in current security systems. We organize quantum-safe methods into significant organizations such as lattice-based, hash-based, multivariate polynomial-based and code-based encrypted communications. Each type has been evaluated critically based on computational efficiency, key sizes, speed of encryption/decryption and security proofs. The survey also examines the current standardization activities happening in the world and especially the U.S. National Institute of Standards and Technology (NIST) PQC competition, which lists candidate algorithms that have advanced to standard adoption. Besides this, the paper addresses hybrid cryptographic designs that use both classical and post-quantum bases in ensuring a seamless migration in the transition phase. Internet security protocols like TLS, VPNs and blockchain consensus as applications of PQC are examined in detail. Lastly, we pinpoint open research issues, which include creating lightweight PQC to support resource-constrained IoT devices, balancing performance and strong security assurances, and interoperability between the new PQC algorithms and existing infrastructures. Through detailed survey we inform the future of researchers, practitioners, and policymakers on the preparation of the post-quantum era of secure digital communications.
In 1994, Peter Shor developed a quantum algorithm that can efficiently solve the factorization and discrete logarithm problems. These problems are the foundation of modern cryptographic algorithms and the existence of an efficient algorithm for solving them threatens their security. Although large-scale quantum computers capable of breaking current cryptographic algorithms are not yet available, advances in quantum technology and the risk of “store now, decrypt later” attacks make it essential to prepare for migration to quantum-safe cryptography today. For the past decade, the cryptographic community has been actively developing algorithms that are not exploitable by Shor’s algorithm; such algorithms are said to be “quantum-safe” or “post-quantum.” However, cryptographic algorithms do not exist in isolation—they are components of larger cryptographic systems, such as protocols or other cryptographic primitives. Migrating these systems to use quantum-safe algorithms is therefore a complex task. This thesis studies the migration of several widely used cryptographic systems to post-quantum cryptography. In particular, we consider the migration of the public-key infrastructure (PKI), the TLS protocol, the XML Encryption and XML Signature standards, the SAML security framework, the Advanced Electronic Signature (AdES) standard, and the password-authenticated public-key encryption (PAPKE) primitive. For each topic, we analyze how the presence of quantum adversaries affects the security of existing constructions and identify components that rely on cryptographic assumptions vulnerable to quantum attacks. Based on this analysis, we propose approaches for adapting these systems to use post-quantum cryptographic algorithms. The proposed solutions are considered in two main forms: purely post-quantum and hybrid post-quantum. Purely post-quantum approaches rely exclusively on post-quantum algorithms, while hybrid post-quantum approaches combine classical and post-quantum mechanisms in order to provide security as long as at least one of the underlying assumptions remains secure. Hybrid post-quantum approaches are primarily motivated by uncertainty regarding the security of post-quantum algorithms. For each proposal, we discuss the advantages and disadvantages of the design, including deployment complexity, compatibility with existing systems, and performance considerations. In several cases, we also provide proof-of-concept implementations and evaluate their performance through benchmarks. We study post-quantum public-key infrastructures, which form a fundamental component of many other cryptographic systems. We show that constructing a purely post-quantum PKI does not fundamentally differ from constructing a classical PKI. For hybrid deployments, we propose two approaches—the composite hybrid and the parallel hybrid—which differ primarily in their implementation complexity. We also survey and analyze existing proposals for post-quantum TLS. In contrast, systems such as XML encryption and XML signatures, the SAML security framework, and the eIDAS-related AdES standard have received little attention in the context of post-quantum migration. For these systems, we outline possible migration approaches and provide proof-of-concept implementations. In addition, we present an example migration plan for a Trust Service Provider that relies on all of the discussed cryptographic systems, together with the methodology used to develop it. Finally, we consider the migration of the cryptographic primitive PAPKE. We propose a novel construction that replaces an ideal cipher with a half-ideal cipher, resulting in more efficient quantum-safe constructions and motivating the study of a new public-key encryption property called decryption robustness.
The potential of the swift development of quantum computing is an extreme danger to the traditional cryptographic programs, and they are the foundation of the modern communication infrastructure. RSA and ECC are classical public-key algorithms that can be successfully quantum-attacked, in particular, Shor's algorithm can easily factor large integers and calculate discrete logarithms (Bernstein et al., 2017). The Post-Quantum Cryptography (PQC) has become the key to secure the next-generation communication networks against these threats, which relies on lattice problem-based algorithms, hash-based based algorithms, multivariate polynomials-based algorithms, and code-based cryptography. The paper examines the concepts, design, and implementation issues of PQC within current network infrastructure focusing on the secure transmission of data, authentication, and key management in the upcoming 5G and 6G networks. The approach will include the survey of existing algorithms of PQC, model the integration of protocol in the communication systems and test computational efficiency, security strength, and scalability. It has been found that PQC is suitable to protect network communications against quantum attackers, and achieves reasonable performance, though trade-offs can be seen in terms of computation overhead, key size, and latency. The research offers understanding to the researcher, network engineers and policy makers in order to adopt quantum resistant cryptography protocols to secure the confidentiality, integrity and authenticity of information in the future communication networks.