Physical Review Research

Efficient and secure quantum secret sharing for eight users

Yue Qin, Jialin Cheng, Jingxu Ma, Di Zhao, Zhihui Yan, Xiaojun Jia, Changde Xie, Kunchi Peng

Published Jul 8, 2024• 40 citations

Abstract

Quantum secret sharing (QSS) has emerged as a promising avenue for storing secret with quantum-enhanced security. However, practical applications are hindered by the challenge for simultaneously implementing high-efficiency, high-security, and high-flexibility QSS with multiple users. Here we present an efficient, secure, and flexible QSS involving eight users with a continuous-variable eight-partite bound entanglement (BE) state, where only two nondegenerated optical parameter amplifiers are required. Such abilities are attributed to the generation of the eight-partite BE state with precise phase controlling systems and a large entanglement network, and fiber distribution with polarization-division multiplexing. In the QSS, a higher key rate can be demonstrated, when a secret is extracted through flexible combinations of more collaborative users. Our system may pave the way for the spatially separated multiuser quantum communications, while minimizing quantum hardware. Published by the American Physical Society 2024

DOI: 10.1103/physrevresearch.6.033036

Related papers

Experimental Efficient Source-Independent Quantum Secret Sharing against Coherent Attacks

Yi-Ran Xiao, Hua-Lei Yin, Wen-Ji Hua +2 more

Source-independent quantum secret sharing (SI QSS), while essential for secure multiuser cryptographic operations in quantum networks, faces significant implementation challenges stemming from the inherent complexity of generating and distributing multipartite entangled states. Recently, a resource-efficient SI QSS protocol utilizing entangled photon pairs combined with a postmatching method has been proposed to address this limitation. In this Letter, we report an experimental demonstration of this protocol using high-fidelity polarization-entangled photon pairs in a star topology. For a three-user network, we obtain secure key rates of 21.18, 4.69, and 1.71 kbps under single-user channel losses of 7.6, 10.9, and 12.9 dB respectively. Furthermore, under conditions of equal channel loss per user, we achieve secure key rates of 6.97, 6.46, and 5.88 kbps for three-, four-, and five-user scenarios respectively. These results demonstrate the advantageous independence of the key rate from the number of users. Our work paves the way for large-scale deployment of SI QSS in multiuser quantum networks.

quant-pharXiv:2512.18325Physical Review LettersDec 23, 202517 citations

Quantum secret sharing with four components based on different entangled state optical fields

FANG Yutong, Yaoyao Zhou, WANG Yukun

Quantum secret sharing （QSS） is one of the important branches of quantum cryptography， which is used to share a secret among multiple participants， and has great potential for applications in fields such as quantum computing and quantum communication. With the rapid development of quantum information， people have higher requirements for the number of users and security of quantum secret sharing. This article analyzes the entanglement characteristics of three entangled states， namely the continuous variable four component Bound Entanglement （BE） state， GHZ （Greenberger-Horn-Zeilinger） state， and Cluster state， and uses them as quantum resources to construct a four component quantum secret sharing scheme. The dependence of quantum secret sharing security on different physical parameters is theoretically calculated for each scheme. The results show that the secret key rate of different entangled state optical fields has a consistent relationship with the signal strength when four users cooperate. While the secret key rate in the BE entangled-state light field corresponding to the QSS scheme is balanced in orthogonal amplitude and orthogonal bit-phase components with a symmetric relationship when three users cooperate， the GHZ entangled-state and the Cluseter entangled-state light field corresponding to the QSS scheme show a larger secret key rate in a single orthogonal component.

Mar 1, 20260 citations

Secure quantum secret sharing without signal disturbance monitoring

Jie Gu, Yuan-Mei Xie, Wen‐Bo Liu +3 more

Quantum secret sharing (QSS) is an essential primitive for the future quantum internet, which promises secure multiparty communication. However, developing a large-scale QSS network is a huge challenge due to the channel loss and the requirement of multiphoton interference or high-fidelity multipartite entanglement distribution. Here, we propose a three-user QSS protocol without monitoring signal disturbance, which is capable of ensuring the unconditional security. The final key rate of our protocol can be demonstrated to break the Pirandola-Laurenza-Ottaviani-Banchi bound of quantum channel and its simulated transmission distance can approach over 600 km using current techniques. Our results pave the way to realizing high-rate and large-scale QSS networks.

arXiv:2104.10321Optics ExpressSep 16, 202146 citations

Frequency-subspace encoding for multiplexed quantum secret sharing

Meritxell Cabrejo‐Ponce, Carlos Sevilla-Gutiérrez, Christopher Spiess +4 more

Quantum secret sharing (QSS) is a multi-party quantum communication protocol that can be realized with bipartite entanglement and relative phase encoding. Previous implementations typically encoded the phase in the pump, applying it across the entire source bandwidth, thereby limiting scalability via wavelength multiplexing. In contrast, we present a variant of the standard QSS protocol that leverages frequency correlations to connect multiple users with a single source. The secret owner, who has access to the source, encodes classical information by applying frequency-dependent phase modulation to a broadband polarization-entangled photon pair. Each frequency channel, therefore, provides an independent QSS session among the secret owner and a pair of users. We demonstrate state fidelities of at least 90% for a channel pair of the 200 GHz ITU grid, a configuration that can be extended to more than 40 frequency bins for the same grid spacing. Notably, despite the use of large grid spacing and the experimental limitations, the system achieves full connectivity of a network of 7 users while maintaining a key fraction of 0.4 bits/photon. These results provide a resource-efficient path toward multi-user secret sharing over wavelength-multiplexed networks, eliminating the need for multiple two-photon or multi-photon sources.

arXiv:2508.03295Optica QuantumOct 31, 20251 citation

Efficient quantum secret sharing protocol without the basis matching

Cheng Zhang, Fu-Le Hao, Shi‐Pu Gu +7 more

Quantum secret sharing (QSS) is a typical multipartite cryptographic primitive, which is an important part of quantum communication network. Existing QSS protocols generally require basis matching, which would waste the precious quantum resource and increase the classical communication round. Moreover, the basis selection makes QSS face weak random security vulnerabilities. We propose an efficient QSS protocol without the basis matching. In the protocol, the dealer and partners share a polarization-momentum hyperentangled Greenberger-Horne-Zeilinger (GHZ) state and encode keys in the polarization degree of freedom (DOF). The dealer decodes the transmitted keys relying on the nonlocal hyperentanglement-assisted polarization GHZ state analysis. Our QSS protocol is unconditionally secure in theory. We develop simulation method to estimate its performance in practical environment. Our protocol has three advantages. First, it does not require the basis matching and can completely distinguish eight encoded polarization GHZ states, which increases the utilization rate of entanglement resources to 100 % and increases the key generation rate by an order of magnitude. Second, it only requires one round of classical communication, and thus reduces the key generation time by 69.4 % . Third, it can eliminate the weak random security vulnerabilities associated with the basis selection and enhance QSS’s practical security. Meanwhile, our protocol only uses linear optical elements, which makes it practically feasible. Our QSS protocol has application potential in the future quantum communication network.

Fundamental ResearchNov 1, 20251 citation

High-efficient long-distance device-independent quantum secret sharing based on single-photon sources

Qi Zhang, Cheng Zhang, Wei Zhong +3 more

Device-independent quantum secret sharing (DI QSS) relaxes security assumptions of experimental devices to provide the highest security level for QSS. Previous DI QSS protocols require to generate multi-partite entangled states and then implement the long-distance entanglement distribution. The extremely low generation probability of current multi-partite entanglement source and photon transmission loss largely limit DI QSS's practical key generation rate and secure photon transmission distance. In the paper, we propose a high-efficient long-distance DI QSS protocol based on practical nearly on-demand single-photon sources (SPSs), which adopts the single photons and heralded architecture to construct long-distance multi-partite entanglement channels. Our SPS DI QSS protocol can automatically eliminate the negative influence from photon transmission loss and largely increase the secure photon transmission distance. Moreover, we adopt active improvement strategies such as random key generation basis, postselection, and advanced postselection to further increase the practical key generation rate and lower the experimental requirement. Comparing with previous DI QSS protocols based on entanglement sources, our SPS DI QSS protocol can increase the practical communication efficiency by six orders of magnitude, and increase the secure photon transmission distance by at least 151 times. This SPS DI QSS protocol is feasible with the current experimental technologies. Our protocol makes it possible to realize high-efficient long-distance DI network in the near future.

arXiv:2505.10797May 16, 20250 citations