International Conference on Quantum Communications, Networking, and Computing (QCNC)
SDN-Based Hybrid Quantum-Safe Domain Intercommunication Within MadQCI
Rubén B. Méndez, Jaime S. Buruaga, Rafael J. Vicente, Luis Mengual, Antonio Pastor, Alejandro Muñiz, Juan Morales, Rafael Canto, Jesús Folgueira, Diego R. Lopez, Vicente Martín, Juan P. Brito
The importance of quantum-key-distribution (QKD) networks is growing rapidly, not only because the underlying QKD protocol is immune against any (known or unknown) attacks but also as these infrastructures can be operated in a hybrid mode, together with emerging quantum safe, or post quantum cryptography (PQC), public key protocols. Hybrid solutions appear to be the most promising remedy against real-world security risks, posed by prospective quantum computers. Simultaneously, telecommunication operators are embracing novel network paradigms, such as software-defined networking (SDN), due to distinct advantages over traditional approaches. SDN-inspired architectures can also be used for QKD and hybrid QKD-PQC networks. These architectures allow a seamless integration of QKD and hybrid QKD-PQC into production networks, significantly increasing the security of the latter. However, there has only been very limited research on optimal strategies for establishing hybrid connectivity across different organizational domains. The present contribution introduces two methods on interconnecting different technological and administrative domains for such networks. The proposed scheme is QKD-vendor independent and relies heavily on standard and open interfaces. It enables a complete end-to-end communication between applications running on nodes in different domains. It can be used for the secure interconnection of different SDN-based telecommunication domains with additional QKD / hybrid protection and has been tested within the Madrid Quantum-Communication Infrastructure.
The importance of quantum-key-distribution (QKD) networks is growing rapidly, not only because the underlying QKD protocol is immune against any (known or unknown) attacks but also as these infrastructures can be operated in a hybrid mode, together with emerging quantum safe, or post quantum cryptography (PQC), public key protocols. Hybrid solutions appear to be the most promising remedy against real-world security risks, posed by prospective quantum computers. Simultaneously, telecommunication operators are embracing novel network paradigms, such as software-defined networking (SDN), due to distinct advantages over traditional approaches. SDN-inspired architectures can also be used for QKD and hybrid QKD-PQC networks. These architectures allow a seamless integration of QKD and hybrid QKD-PQC into production networks, significantly increasing the security of the latter. However, there has only been very limited research on optimal strategies for establishing hybrid connectivity across different organizational domains. The present contribution introduces two methods on interconnecting different technological and administrative domains for such networks. The proposed scheme is QKD-vendor independent and relies heavily on standard and open interfaces. It enables a complete end-to-end communication between applications running on nodes in different domains. It can be used for the secure interconnection of different SDN-based telecommunication domains with additional QKD / hybrid protection and has been tested within the Madrid Quantum-Communication 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 growing dependence on digital communications underscores the need to protect data as it travels through the network. Internet Protocol Security (IPsec) plays a central role, providing a robust framework to ensure the confidentiality, integrity, and authenticity of transmitted data. However, advances in Quantum Computing pose a significant threat to current public-key cryptographic schemes by enabling efficient solutions to factoring and discrete logarithm problems. A promising solution also arises from the quantum domain. Quantum Key Distribution (QKD) provides a security layer immune to any computational attacks, whether quantum or classical. While the rapid adoption of quantum-safe technologies is highly desirable, it is equally important to ensure the resilience of existing trusted infrastructures, as the introduction of novel technologies may also entail unforeseen challenges. Enabling an evolutionary path that brings our current security infrastructure to a quantum-safe one, protected against both present and future threats, is thus very important. This work proposes a solution that integrates emerging quantum technologies into the existing security and communications infrastructure to ensure long-term protection. We focus on IPsec —one of the most widely deployed security protocols— and combine it with Software-Defined Networking (SDN) and QKD to construct a novel network security infrastructure that is resilient against both classical and quantum computational threats. Building upon recent standardization initiatives and operational tools for QKD integration, we demonstrate advanced capabilities -including rekeying and secure key transport- on a field deployed QKD network operating within a shared quantum-classical 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.
Quantum Key Distribution (QKD) is one of the major cryptographic solutions to tackle the security threats associated to future computational advances, in particular those coming from quantum computing. At the most simple level, QKD can be seen as a highly secure source of symmetric secret keys in two separated places. Nonetheless, the lack of standardization and the strong requirements from the physical layer makes this technology very difficult to integrate in existing infrastructure.However, the success of QKD networks radically depends on the degree in which they can be adopted in the existing infrastructure, and it is a must that it happens via standard protocols and interfaces. The flexibility of novel network paradigms, like Software-Defined Networking (SDN), allows for a faster adoption of new concepts, hardware and services in telecommunications networks. This paradigm can be used for quantum communications, allowing for a fast and scalable deployment of quantum technologies and services in the telecommunications network to a degree that was simply impossible in previous schemes, where the different network devices and their connections should be modified, one by one, to create a quantum communications channel.This tutorial provides an introduction to existing QKD technologies and networks, followed by a descriptive explanation on how SDN principles can be utilized to abstract and integrate QKD systems as part of the network management. This will help to reduce the time-to-market for quantum technologies, and also will make quantum cryptography available as a service to be capitalized by the network operators.
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.