Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2411.01086

Practical hybrid PQC-QKD protocols with enhanced security and performance

Zeng, Pei, Bandyopadhyay, Debayan, Méndez, José A. Méndez, Nolan Bitner, Alexander Kolar, Michael T. Solomon, Ziyu Ye, Filip Rozpędek, Tian Zhong, F. Joseph Heremans, D. D. Awschalom, Liang Jiang, Junyu Liu

Published Nov 2, 2024• 4 citations
arXivHTMLPDF

Abstract

Quantum resistance is vital for emerging cryptographic systems as quantum technologies continue to advance towards large-scale, fault-tolerant quantum computers. Resistance may be offered by quantum key distribution (QKD), which provides information-theoretic security using quantum states of photons, but may be limited by transmission loss at long distances. An alternative approach uses classical means and is conjectured to be resistant to quantum attacks, so-called post-quantum cryptography (PQC), but it is yet to be rigorously proven, and its current implementations are computationally expensive. To overcome the security and performance challenges present in each, here we develop hybrid protocols by which QKD and PQC inter-operate within a joint quantum-classical network. In particular, we consider different hybrid designs that may offer enhanced speed and/or security over the individual performance of either approach. Furthermore, we present a method for analyzing the security of hybrid protocols in key distribution networks. Our hybrid approach paves the way for joint quantum-classical communication networks, which leverage the advantages of both QKD and PQC and can be tailored to the requirements of various practical networks.

DOI
10.48550/arxiv.2411.01086

Related papers

Towards efficient and secure quantum-classical communication networks

Pei Zeng, Debayan Bandyopadhyay, José A. Méndez Méndez +7 more

The rapid advancement of quantum technologies calls for the design and deployment of quantum-safe cryptographic protocols and communication networks. There are two primary approaches to achieving quantum-resistant security: quantum key distribution (QKD) and post-quantum cryptography (PQC). While each offers unique advantages, both have drawbacks in practical implementation. In this work, we introduce the pros and cons of these protocols and explore how they can be combined to achieve a higher level of security and/or improved performance in key distribution. We hope our discussion inspires further research into the design of hybrid cryptographic protocols for quantum-classical communication networks.

arXiv:2411.01081•IEEE International Conference on Trust, Privacy and Security in Intelligent Systems and Applications (TPS-ISA)•Oct 28, 2024•3 citations

Enhanced Network Security Protocols for the Quantum Era: Combining Classical and Post-Quantum Cryptography, and Quantum Key Distribution

Carlos Rubio García, Abraham Cano Aguilera, Catalina Stan +3 more

The emergence of quantum computing poses a threat to classical cryptography algorithms, necessitating a shift to quantum secure cryptography. Hybrid protocols combining at least one classical and one quantum-resistant cryptographic algorithm are becoming the standard for securing communications. In this work, we present our novel solution for integrating three different cryptographic assumptions (two of them quantumresistant) into hybrid network security protocols, ensuring that three different cryptographic assumptions must be broken before the protocol becomes vulnerable. Our solution allows for a seamless integration of classical and post-quantum (PQ) cryptography, and quantum key distribution (QKD) into existing network security protocols (e.g., TLS, IPsec) without any major modifications to the protocols themselves. This crypto-agility ensures the mitigation of some of the most well known challenges of both PQ cryptography and QKD. Our findings demonstrate the feasibility of such triple-hybrid network security protocols, showing non-substantial decrease in performance and almost no added packet overhead compared to state of the art protocols. In exchange, we pave the way towards next generation networks where the potential of new quantum-resistant cryptographic schemes can be leveraged in a dynamic and agile fashion, thus fostering a new era of unbreakable communication systems.

IEEE Journal on Selected Areas in Communications•May 13, 2025•37 citations

A PQC and QKD Hybridization for Quantum-Secure Communications

Dominik Marchsreiter, Johanna Sepúlveda

Large quantum computers will be able to break the cryptographic algorithms on which current secure communications rely on. Post-Quantum Cryptography (PQC) and Quantum key distribution (QKD) are two security technologies that show protection capabilities against the latent quantum threat. While PQC relies on different hard mathematical problems to develop a wide variety of cryptographic operations, QKD is based on quantum physics laws to generate and distribute symmetric cryptographic keys through different QKD protocols. These keys can be used by different applications to perform security transformations. QKD still requires authentication to prevent man-in-the-middle attacks. The hybridization of PQC and QKD is an important step for future secure infrastructures, being able to provide long-term security. In this work we propose authenticated QKD approaches that rely on pre-shared keys and hybrid PQC/QKD alternatives and which are able to securely exchange secret QKD keys through authenticated channels. We identify the different configuration alternatives and their parameters, as well as we develop a wide performance evaluation. Results show that pre-shared keys and PQC-based authentication through Dilithium algorithm are the fastest alternatives. Also, we show the potential of the T12 QKD protocol.

Euromicro Conference on Digital System Design (DSD)•Sep 6, 2023•16 citations

A Hybrid Framework for Quantum-Resistant TLS Handshakes with PQC, QKD and Classical Cryptography

D. B. K. De Zoysa, M. V. V. Perera, H. D. Weerasinghe

The emergence of large-scale quantum computers poses a significant threat to current cryptographic protocols, particularly Transport Layer Security (TLS), which relies on RSA and elliptic curve cryptography vulnerable to Shor's algorithm. This paper presents a hybrid framework for quantum-resistant TLS handshakes that integrates post-quantum cryptography (PQC), quantum key distribution (QKD) and classical cryptography to provide comprehensive protection against both classical and quantum attacks. The approach employs three QKD protocols; BB84, E91, and Measurement-Device-Independent QKD (MDI-QKD) alongside NIST-standardized PQC algorithms as well as alternative candidates such as HQC and BIKE. A key innovation is the QKD key management module, which addresses performance bottlenecks through periodic key generation and secure reuse within predefined retention periods, significantly reducing QKD overhead in TLS handshakes. The experimental implementation using the quantum network simulator evaluated 144 distinct cryptographic protocol combinations. Results demonstrate that ML-KEM combined with ML-DSA provides optimal PQC performance, while QKD protocol selection is distance-dependent: BB84 for short-range and MDI-QKD for long-distance communication. The framework includes various attack mitigation mechanisms and ensure security as long as at least one cryptographic method remains uncompromised. Consistent with current global quantum network usage, the proposed TLS approach is designed primarily for MAN and WAN environments rather than the Internet, providing a balanced solution that combines theoretical security guarantees with computational efficiency.

International Conference on Advances in Technology and Computing (ICATC)•Dec 16, 2025•1 citation

Quantum Key Distribution in the Post-Quantum Era: Technologies and Deployment Perspectives

Sara Alshehri, Amani Ibraheem

Quantum computing advances pose a serious threat to conventional public-key cryptographic systems such as RSA and elliptic curve cryptography as quantum algorithms may undermine the computational assumptions that guaranty their security. This challenge has driven the development of quantumsafe security approaches among which Quantum Key Distribution (QKD) represents a fundamentally different paradigm based on quantum mechanical principles rather than mathematical complexity. This paper presents a structured review of recent progress in QKD based on a systematic analysis of literature between 2020 and 2025, we examine core protocols including discrete-variable, continuous-variable, measurement-deviceindependent, and twin-field approaches, while also discussing their relationship with post-quantum cryptography as a complementary strategy for future secure communication systems. We provide a unified comparison framework to support practical design and policy decisions by organizing protocols and implementations along deployment dimensions. The study analyze theoretical foundations, implementation technologies across fiber, free-space, satellite, and integrated photonic platforms, and key performance trade-offs involving scalability, security robustness, and deployment feasibility. Findings indicate substantial progress in transitioning QKD from laboratory research toward practical implementations, supported by advances in network architectures, integrated hardware and hybrid cryptographic designs. The comparative analysis will highlight distinct strengths and limitations among protocol families and emphasize the potential of combining QKD with post-quantum cryptographic methods to enhance resilience. Remaining challenges including scalability constraints, implementation-level vulnerabilities, performance limitations over long distances, and integration with existing communication infrastructures are critically discussed. Finally, emerging research directions such as quantum repeaters, hybrid quantum-classical security models, and exploratory directions such as artificial intelligence-assisted optimizations are identified as key factors in enabling the evolution of QKD toward largescale quantum-secure networking.

International Conference on Electronics, Computer and Computation•Apr 10, 2026•1 citation

Quantum Key Distribution with Enhanced PQC Validation

Vlad Beraru, Carmen MILEA

Quantum Key Distribution (QKD) provides information-theoretic security based on quantum mechanics, but its practical deployment is limited by its reliance on classical infrastructure and inability to operate as a standalone solution.Recent research emphasizes hybrid approaches that combine QKD with post-quantum cryptography (PQC) to achieve practical and robust security.This paper presents a hybrid key distribution model integrating QKD with the postquantum key encapsulation mechanism.The two independently generated keys are combined to derive a unified shared secret, enhancing resilience against both classical and quantum adversaries.The system is implemented using a simulated quantum environment, enabling the emulation of quantum communication over classical networks.The proposed approach is validated through a secure image transmission use case, demonstrating the correctness of the hybrid key exchange.The results highlight the feasibility of hybrid classical-quantum cryptographic systems as a practical step toward secure communication in emerging quantum network infrastructures.

Informatica Economica•Jun 30, 2026•0 citations
Quantum resistance is vital for emerging cryptographic systems as quantum technologies continue to advance towards large-scale, fault-tolerant quantum computers. Resistance may be offered by quantum key distribution (QKD), which provides information-theoretic security using quantum states of photons, but may be limited by transmission loss at long distances. An alternative approach uses classical means and is conjectured to be resistant to quantum attacks, so-called post-quantum cryptography (PQC), but it is yet to be rigorously proven, and its current implementations are computationally expensive. To overcome the security and performance challenges present in each, here we develop hybrid protocols by which QKD and PQC inter-operate within a joint quantum-classical network. In particular, we consider different hybrid designs that may offer enhanced speed and/or security over the individual performance of either approach. Furthermore, we present a method for analyzing the security of hybrid protocols in key distribution networks. Our hybrid approach paves the way for joint quantum-classical communication networks, which leverage the advantages of both QKD and PQC and can be tailored to the requirements of various practical networks.
The rapid advancement of quantum technologies calls for the design and deployment of quantum-safe cryptographic protocols and communication networks. There are two primary approaches to achieving quantum-resistant security: quantum key distribution (QKD) and post-quantum cryptography (PQC). While each offers unique advantages, both have drawbacks in practical implementation. In this work, we introduce the pros and cons of these protocols and explore how they can be combined to achieve a higher level of security and/or improved performance in key distribution. We hope our discussion inspires further research into the design of hybrid cryptographic protocols for quantum-classical communication networks.
The emergence of quantum computing poses a threat to classical cryptography algorithms, necessitating a shift to quantum secure cryptography. Hybrid protocols combining at least one classical and one quantum-resistant cryptographic algorithm are becoming the standard for securing communications. In this work, we present our novel solution for integrating three different cryptographic assumptions (two of them quantumresistant) into hybrid network security protocols, ensuring that three different cryptographic assumptions must be broken before the protocol becomes vulnerable. Our solution allows for a seamless integration of classical and post-quantum (PQ) cryptography, and quantum key distribution (QKD) into existing network security protocols (e.g., TLS, IPsec) without any major modifications to the protocols themselves. This crypto-agility ensures the mitigation of some of the most well known challenges of both PQ cryptography and QKD. Our findings demonstrate the feasibility of such triple-hybrid network security protocols, showing non-substantial decrease in performance and almost no added packet overhead compared to state of the art protocols. In exchange, we pave the way towards next generation networks where the potential of new quantum-resistant cryptographic schemes can be leveraged in a dynamic and agile fashion, thus fostering a new era of unbreakable communication systems.
Large quantum computers will be able to break the cryptographic algorithms on which current secure communications rely on. Post-Quantum Cryptography (PQC) and Quantum key distribution (QKD) are two security technologies that show protection capabilities against the latent quantum threat. While PQC relies on different hard mathematical problems to develop a wide variety of cryptographic operations, QKD is based on quantum physics laws to generate and distribute symmetric cryptographic keys through different QKD protocols. These keys can be used by different applications to perform security transformations. QKD still requires authentication to prevent man-in-the-middle attacks. The hybridization of PQC and QKD is an important step for future secure infrastructures, being able to provide long-term security. In this work we propose authenticated QKD approaches that rely on pre-shared keys and hybrid PQC/QKD alternatives and which are able to securely exchange secret QKD keys through authenticated channels. We identify the different configuration alternatives and their parameters, as well as we develop a wide performance evaluation. Results show that pre-shared keys and PQC-based authentication through Dilithium algorithm are the fastest alternatives. Also, we show the potential of the T12 QKD protocol.
The emergence of large-scale quantum computers poses a significant threat to current cryptographic protocols, particularly Transport Layer Security (TLS), which relies on RSA and elliptic curve cryptography vulnerable to Shor's algorithm. This paper presents a hybrid framework for quantum-resistant TLS handshakes that integrates post-quantum cryptography (PQC), quantum key distribution (QKD) and classical cryptography to provide comprehensive protection against both classical and quantum attacks. The approach employs three QKD protocols; BB84, E91, and Measurement-Device-Independent QKD (MDI-QKD) alongside NIST-standardized PQC algorithms as well as alternative candidates such as HQC and BIKE. A key innovation is the QKD key management module, which addresses performance bottlenecks through periodic key generation and secure reuse within predefined retention periods, significantly reducing QKD overhead in TLS handshakes. The experimental implementation using the quantum network simulator evaluated 144 distinct cryptographic protocol combinations. Results demonstrate that ML-KEM combined with ML-DSA provides optimal PQC performance, while QKD protocol selection is distance-dependent: BB84 for short-range and MDI-QKD for long-distance communication. The framework includes various attack mitigation mechanisms and ensure security as long as at least one cryptographic method remains uncompromised. Consistent with current global quantum network usage, the proposed TLS approach is designed primarily for MAN and WAN environments rather than the Internet, providing a balanced solution that combines theoretical security guarantees with computational efficiency.
Quantum computing advances pose a serious threat to conventional public-key cryptographic systems such as RSA and elliptic curve cryptography as quantum algorithms may undermine the computational assumptions that guaranty their security. This challenge has driven the development of quantumsafe security approaches among which Quantum Key Distribution (QKD) represents a fundamentally different paradigm based on quantum mechanical principles rather than mathematical complexity. This paper presents a structured review of recent progress in QKD based on a systematic analysis of literature between 2020 and 2025, we examine core protocols including discrete-variable, continuous-variable, measurement-deviceindependent, and twin-field approaches, while also discussing their relationship with post-quantum cryptography as a complementary strategy for future secure communication systems. We provide a unified comparison framework to support practical design and policy decisions by organizing protocols and implementations along deployment dimensions. The study analyze theoretical foundations, implementation technologies across fiber, free-space, satellite, and integrated photonic platforms, and key performance trade-offs involving scalability, security robustness, and deployment feasibility. Findings indicate substantial progress in transitioning QKD from laboratory research toward practical implementations, supported by advances in network architectures, integrated hardware and hybrid cryptographic designs. The comparative analysis will highlight distinct strengths and limitations among protocol families and emphasize the potential of combining QKD with post-quantum cryptographic methods to enhance resilience. Remaining challenges including scalability constraints, implementation-level vulnerabilities, performance limitations over long distances, and integration with existing communication infrastructures are critically discussed. Finally, emerging research directions such as quantum repeaters, hybrid quantum-classical security models, and exploratory directions such as artificial intelligence-assisted optimizations are identified as key factors in enabling the evolution of QKD toward largescale quantum-secure networking.
Quantum Key Distribution (QKD) provides information-theoretic security based on quantum mechanics, but its practical deployment is limited by its reliance on classical infrastructure and inability to operate as a standalone solution.Recent research emphasizes hybrid approaches that combine QKD with post-quantum cryptography (PQC) to achieve practical and robust security.This paper presents a hybrid key distribution model integrating QKD with the postquantum key encapsulation mechanism.The two independently generated keys are combined to derive a unified shared secret, enhancing resilience against both classical and quantum adversaries.The system is implemented using a simulated quantum environment, enabling the emulation of quantum communication over classical networks.The proposed approach is validated through a secure image transmission use case, demonstrating the correctness of the hybrid key exchange.The results highlight the feasibility of hybrid classical-quantum cryptographic systems as a practical step toward secure communication in emerging quantum network infrastructures.