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.
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.
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.
The large-scale deployment of quantum secret sharing (QSS) in quantum networks is currently challenging due to the requirements for the generation and distribution of multipartite entanglement states. Here we present an efficient source-independent QSS protocol utilizing entangled photon pairs in quantum networks. Through the post-matching method, which means the measurement events in the same basis are matched, the key rate is almost independent of the number of participants. In addition, the unconditional security of our QSS against internal and external eavesdroppers can be proved by introducing an equivalent virtual protocol. Our protocol has great performance and technical advantages in future quantum networks.
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
Superconducting microwave quantum networks is a rapidly developing field, enabling distributed quantum computing and holding a promise for hybrid architectures in quantum internet. Quantum secret sharing (QSS) is one of the key protocols for multipartite quantum networks and can provide an unconditionally secure way to share quantum states among n players. Using microwave two-mode squeezed states as an entanglement resource, we experimentally implement a QSS protocol with n=3, where a subset of at least k=2 players must collaborate to faithfully reconstruct the original secret state. We demonstrate reconstructed-state fidelities that surpass the asymptotic no-cloning threshold of Fnc=2/3 and identify a parameter regime that allows for unconditionally secure communication in the presence of an omnipotent dishonest player. Furthermore, we experimentally explore inherent connections between QSS and other important quantum information processing tasks, such as quantum dense coding and elementary quantum error correction of channel erasures. Finally, we discuss extensions of QSS and its relation to the concept of blind quantum computing.
Quantum secret sharing (QSS) is essential for multiparty quantum communication, which is one of cornerstones in the future quantum internet. However, a linear rate-distance limitation severely constrains the secure key rate and transmission distance of QSS. Here, we present a practical QSS protocol among three participants based on the differential phase shift scheme and twin field ideas for the solution of high-efficiency multiparty communication task. In contrast to a formerly proposed differential phase shift QSS protocol, our protocol can break the linear rate-distance bound, theoretically improving the secret key rate by three orders of magnitude in a 300-km-long fiber. Furthermore, the new protocol is secure against Trojan horse attacks that cannot be resisted by previous differential phase shift QSS.
Quantum secret sharing (QSS) plays a significant role in multiparty quantum communication and is a crucial component of future quantum multiparty computing networks. Therefore, it is highly valuable to develop a QSS protocol that offers both information-theoretic security and validation in real optical systems under a finite-key regime. In this work, we propose a three-user QSS protocol based on phase-encoding technology. By adopting symmetric procedures for the two players, our protocol resolves the security loopholes introduced by asymmetric basis choice without prior knowledge of the identity of the malicious player. Kato's concentration inequality is exploited to provide security against coherent attacks with the finite-key effect. Moreover, the practicality of our protocol has been validated under a 30-dB channel loss with a transmission distance of 5-km fiber. Our protocol achieves secure key rates ranging from 432 to 192 bps by choosing different pulse intensities and basis selection probabilities. Offering enhanced security and practicality, our protocol stands as an essential element for the realization of quantum multiparty computing networks.