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

Experimental demonstration of multiparty reference-frame-independent QKD

Donghwa Lee, Kyujin Shin, Yosep Kim, Hyang‐Tag Lim, Yong‐Su Kim

Published Jan 1, 2023• 0 citations
Publisher

Abstract

We report that RFI-QKD protocol can be extended to multiparty system using Greenberger-Horne-Zeilinger (GHZ) state. We derive the asymptotic key rate and perform proof-of-principle experiment to verify the feasibility of secure quantum network.
DOI
10.1364/cleo_fs.2023.ff2a.2

Related papers

Multipartite reference-frame-independent quantum cryptographic communication

Donghwa Lee, Kyujin Shin, Hyang-Tag Lim +2 more

Reference frame mismatch among communication parties introduces errors in quantum cryptographic protocols. As the number of participants increases, aligning reference frames becomes increasingly difficult, complicating multipartite quantum cryptographic implementations. Here, we theoretically and experimentally investigate multipartite reference-frame-independent (RFI) quantum cryptographic communication using Greenberger-Horne-Zeilinger (GHZ) states. We generalize the bipartite RFI security parameter $C$ to an $N$-party parameter $C_N$ and derive the asymptotic secret key rate expressed solely in terms of experimentally accessible quantities. We analyze the key rate under global and local depolarizing noise models and find that increasing the number of parties $N$ enhances robustness against global depolarizing noise while increasing vulnerability to local channel noise. We also present a proof-of-principle experimental demonstration of four-party RFI quantum cryptographic communication using four-photon GHZ states, confirming the reference-frame invariance of both the $C_4$ parameter and the secret key rate under various reference frame rotations.

quant-pharXiv:2606.12284•Jun 11, 2026•0 citations

Reference-Frame-Independent Quantum Key Distribution Using Fewer States

Hongwei Liu, Jipeng Wang, Haiqiang Ma +1 more

In secure communication, reference-frame calibration is critical to ensuring a secure key rate in quantum key distribution (QKD) systems. This process also increases the complexity of the system, which is not conducive to practical use. Although the reference-frame-independent (RFI) QKD protocol can simplify alignment, it requires three bases to prepare six states. Here the authors present instead a three-state RFI QKD protocol, and verify its security using a recently developed proof based on semidefinite programming. A proof-of-principle experiment is conducted to demonstrate the feasibility of the scheme. This work is sure to boost the practical application of the RFI QKD protocol.

arXiv:1811.03244•Physical Review Applied•Sep 19, 2019•40 citations

Reference-frame-independent, measurement-device-independent quantum key distribution using fewer quantum states

Donghwa Lee, Seongjin Hong, Young‐Wook Cho +6 more

Reference-frame-independent quantum key distribution (RFI-QKD) provides a practical way to generate secret keys between two remote parties without sharing common reference frames. On the other hand, measurement-device-independent QKD (MDI-QKD) offers a high level of security, as it is immune to all quantum hacking attempts to measurement devices. The combination of these two QKD protocols, i.e., RFI-MDI-QKD, is one of the most fascinating QKD protocols, since it holds advantages of both practicality and security. For further practicality of RFI-MDI-QKD, it is beneficial to reduce the implementation complexity. Here, we show that RFI-MDI-QKD can be implemented using fewer quantum states than those of its original proposal. We find that, in principle, the number of quantum states for one of the parties can be reduced from six to three without compromising security. Compared to conventional RFI-MDI-QKD where both parties transmit six quantum states, it significantly simplifies the implementation of the QKD protocol. We also verify the feasibility of the scheme with a proof-of-principle experiment.

arXiv:2002.01601•Optics Letters•Mar 30, 2020•23 citations

Demonstration of a 6 state-4 state reference frame independent channel for quantum key distribution

Ramy Tannous, Zhangdong Ye, Jeongwan Jin +3 more

We study a reference frame independent (RFI) quantum key distribution (QKD) protocol using six states for Alice and only four states for Bob, while previous RFI protocols require a six state analyzer for Bob. Our protocol can generate a secure key for any possible phase of the entangled state provided the variation is small compared to the measurement rate, as shown by our numerical key rate analysis. We perform a proof-of-principle experiment using polarization entangled photon pairs. In the presence of a varying rotational phase, we obtain a consistently low error rate of less than 4%, indicating the feasibility of this protocol for QKD. Our RFI protocol is hence beneficial but not limited to applications in a satellite or mobile free-space QKD, where a communication node must limit the resources and restrict the number of measured states to four instead of six.

arXiv:1905.09197•Applied Physics Letters•Nov 18, 2019•24 citations

Boosting the Performance of Reference-Frame- Independent Measurement-Device-Independent Quantum Key Distribution

Jing-Yang Liu, Xingyu Zhou, Chunhui Zhang +4 more

Among all present quantum key distribution protocols, the reference-frame-independent measurement-device-independent quantum key distribution (RFI-MDI-QKD) is standing out due to its high security and practicability, since it can not only remove all detector-side-channel attacks, but also relax the requirement of reference-frame calibrations. However, till today, the performance degradation of RFI-MDI-QKD caused by finite-size effects is one of the biggest impediment to its practical implementations. Here, we propose an enhanced RFI-MDI-QKD protocol which is highly resistant to the finite-size effect and immensely boosts both the key rate and transmission distance. As a result, it can even surpass the most advanced MDI-QKD protocol under larger rotation angles of reference frames. Furthermore, with the state-of-the-art RFI-MDI-QKD setup, we successfully carry out a proof-of-principle experimental demonstration at a record distance of 300km. The experiments under non-ideal condition verify the advantage and robustness of our present work.

Journal of Lightwave Technology•Jun 11, 2021•19 citations

Experimental demonstration of 4-state reference-frame-independent quantum key distribution over 200km

Ziran Xie, Tian, Zhiyu, Shi‐Hai Sun

Reference frame independent quantum key distribution (RFI-QKD) has gained widespread attention due to the unique advantage for practical application, as it circumvents the need for active reference frame alignment within the system. However, in comparison to the standard BB84 protocol, the original 6-state RFI protocol requires a greater number of quantum states to be operated by Alice and Bob, which is an aspect that merits optimization. In this work, we propose a 4-state RFI protocol and illustrate that Alice and Bob each require only four quantum states to perform channel estimation that remains independent of reference frame deviation, which can proficiently reduce the system complexity. Furthermore, through numerical simulations taking the finite-size key effect into consideration, we show that 4-state RFI protocol can achieve a secure key rate and transmission distance on par with the original 6-state RFI protocol. Finally, a experiment over 200 km is inplemented to conducted the feasibility of our scheme. We believe that our protocol can streamline the implementation of RFI-QKD and thereby contribute to the practical advancement of RFI-QKD.

arXiv:2405.16518•May 26, 2024•0 citations
Reference frame mismatch among communication parties introduces errors in quantum cryptographic protocols. As the number of participants increases, aligning reference frames becomes increasingly difficult, complicating multipartite quantum cryptographic implementations. Here, we theoretically and experimentally investigate multipartite reference-frame-independent (RFI) quantum cryptographic communication using Greenberger-Horne-Zeilinger (GHZ) states. We generalize the bipartite RFI security parameter CCC to an NNN-party parameter CNC_NCN​ and derive the asymptotic secret key rate expressed solely in terms of experimentally accessible quantities. We analyze the key rate under global and local depolarizing noise models and find that increasing the number of parties NNN enhances robustness against global depolarizing noise while increasing vulnerability to local channel noise. We also present a proof-of-principle experimental demonstration of four-party RFI quantum cryptographic communication using four-photon GHZ states, confirming the reference-frame invariance of both the C4C_4C4​ parameter and the secret key rate under various reference frame rotations.
In secure communication, reference-frame calibration is critical to ensuring a secure key rate in quantum key distribution (QKD) systems. This process also increases the complexity of the system, which is not conducive to practical use. Although the reference-frame-independent (RFI) QKD protocol can simplify alignment, it requires three bases to prepare six states. Here the authors present instead a three-state RFI QKD protocol, and verify its security using a recently developed proof based on semidefinite programming. A proof-of-principle experiment is conducted to demonstrate the feasibility of the scheme. This work is sure to boost the practical application of the RFI QKD protocol.
Reference-frame-independent quantum key distribution (RFI-QKD) provides a practical way to generate secret keys between two remote parties without sharing common reference frames. On the other hand, measurement-device-independent QKD (MDI-QKD) offers a high level of security, as it is immune to all quantum hacking attempts to measurement devices. The combination of these two QKD protocols, i.e., RFI-MDI-QKD, is one of the most fascinating QKD protocols, since it holds advantages of both practicality and security. For further practicality of RFI-MDI-QKD, it is beneficial to reduce the implementation complexity. Here, we show that RFI-MDI-QKD can be implemented using fewer quantum states than those of its original proposal. We find that, in principle, the number of quantum states for one of the parties can be reduced from six to three without compromising security. Compared to conventional RFI-MDI-QKD where both parties transmit six quantum states, it significantly simplifies the implementation of the QKD protocol. We also verify the feasibility of the scheme with a proof-of-principle experiment.
We study a reference frame independent (RFI) quantum key distribution (QKD) protocol using six states for Alice and only four states for Bob, while previous RFI protocols require a six state analyzer for Bob. Our protocol can generate a secure key for any possible phase of the entangled state provided the variation is small compared to the measurement rate, as shown by our numerical key rate analysis. We perform a proof-of-principle experiment using polarization entangled photon pairs. In the presence of a varying rotational phase, we obtain a consistently low error rate of less than 4%, indicating the feasibility of this protocol for QKD. Our RFI protocol is hence beneficial but not limited to applications in a satellite or mobile free-space QKD, where a communication node must limit the resources and restrict the number of measured states to four instead of six.
Among all present quantum key distribution protocols, the reference-frame-independent measurement-device-independent quantum key distribution (RFI-MDI-QKD) is standing out due to its high security and practicability, since it can not only remove all detector-side-channel attacks, but also relax the requirement of reference-frame calibrations. However, till today, the performance degradation of RFI-MDI-QKD caused by finite-size effects is one of the biggest impediment to its practical implementations. Here, we propose an enhanced RFI-MDI-QKD protocol which is highly resistant to the finite-size effect and immensely boosts both the key rate and transmission distance. As a result, it can even surpass the most advanced MDI-QKD protocol under larger rotation angles of reference frames. Furthermore, with the state-of-the-art RFI-MDI-QKD setup, we successfully carry out a proof-of-principle experimental demonstration at a record distance of 300km. The experiments under non-ideal condition verify the advantage and robustness of our present work.
Reference frame independent quantum key distribution (RFI-QKD) has gained widespread attention due to the unique advantage for practical application, as it circumvents the need for active reference frame alignment within the system. However, in comparison to the standard BB84 protocol, the original 6-state RFI protocol requires a greater number of quantum states to be operated by Alice and Bob, which is an aspect that merits optimization. In this work, we propose a 4-state RFI protocol and illustrate that Alice and Bob each require only four quantum states to perform channel estimation that remains independent of reference frame deviation, which can proficiently reduce the system complexity. Furthermore, through numerical simulations taking the finite-size key effect into consideration, we show that 4-state RFI protocol can achieve a secure key rate and transmission distance on par with the original 6-state RFI protocol. Finally, a experiment over 200 km is inplemented to conducted the feasibility of our scheme. We believe that our protocol can streamline the implementation of RFI-QKD and thereby contribute to the practical advancement of RFI-QKD.