Quantum Secret Sharing (QSS) is an essential cryptographic primitive that distributes a secret among multiple parties using quantum information, ensuring that only authorized subsets of participants can reconstruct the secret. Existing QSS approaches predominantly rely on conventional network topologies and maximally entangled states such as the often requiring full participation of all key aspects such as redundancy, authentication, and privacy. In this work, we propose a novel QSS framework built on a generic distributed quantum network that incorporates a threshold-based scheme, allowing any t out of n players to collaboratively reconstruct the secret. Our protocol introduces a custom weighting system and a quantum variant of Dijkstra’s algorithm to dynamically select the optimal subset of players, enhancing flexibility and performance. Furthermore, we integrate CRYSTAL-Kyber post-quantum cryptographic primitives to provide robust user authentication and identity obfuscation, thereby bolstering security and privacy. Through comprehensive security analysis and simulations, we demonstrate that our protocol outperforms traditional QSS models, offering improved resilience against both classical and quantum adversarial threats.
Quantum Secret Sharing (QSS) is an essential cryptographic primitive that distributes a secret among multiple parties using quantum information, ensuring that only authorized subsets of participants can reconstruct the secret. Existing QSS approaches predominantly rely on conventional network topologies and maximally entangled states such as the often requiring full participation of all key aspects such as redundancy, authentication, and privacy. In this work, we propose a novel QSS framework built on a generic distributed quantum network that incorporates a threshold-based scheme, allowing any t out of n players to collaboratively reconstruct the secret. Our protocol introduces a custom weighting system and a quantum variant of Dijkstra’s algorithm to dynamically select the optimal subset of players, enhancing flexibility and performance. Furthermore, we integrate CRYSTAL-Kyber post-quantum cryptographic primitives to provide robust user authentication and identity obfuscation, thereby bolstering security and privacy. Through comprehensive security analysis and simulations, we demonstrate that our protocol outperforms traditional QSS models, offering improved resilience against both classical and quantum adversarial threats.
Quantum secret sharing (QSS) is a cryptographic protocol that leverages quantum mechanics to distribute a secret among multiple parties. With respect to the classical counterpart, in QSS, the secret is encoded into quantum states and shared by a dealer such that only an authorized subsets of participants, i.e., the players, can reconstruct it. Several state-of-the-art studies aim to transpose classical secret sharing into the quantum realm, while maintaining their reliance on traditional network topologies (e.g., star, ring, and fully connected), and require that all thenplayers calculate the secret. These studies exploit the Greenberger–Horne–Zeilinger state, which is a type of maximally entangled quantum state involving three or more qubits. However, none of these works account for redundancy, enhanced security/privacy features, or authentication mechanisms able to fingerprint players. To address these gaps, in this article, we introduce a new concept of QSS, which leans on a generic distributed quantum network, based on a threshold scheme, where all the players collaborate also to the routing of quantum information among them. The dealer, by exploiting a custom flexible weighting system, takes advantage of a newly defined quantum Dijkstra algorithm to select the most suitable subset oftplayers, out of the entire set onnplayers, to involve in the computation. To fingerprint and authenticate users, CRYSTAL-Kyber primitives are adopted, while also protecting each player’s privacy by hiding their identities. We show the effectiveness and performance of the proposed protocol by testing it against the main classical and quantum attacks, thereby improving the state-of-the-art security measures.
Abstract Secret sharing, as an important cryptographic technique, effectively reduces the risk of single points of failure and centralized leakage by distributing secret information across multiple independent entities. With the widespread application of cloud computing and cloud storage, achieving long-term secure storage and controllable recovery of sensitive data in untrusted cloud environments has become a critical issue. Traditional cloud storage solutions face potential risks of security degradation and privacy exposure under long-term operation and future quantum computing threats. This paper proposes a quantum secret sharing (QSS) scheme for cloud storage scenarios, combining the threshold secret sharing with quantum secure communication and quantum information processing to achieve distributed storage and secure reconstruction of secret information across multiple cloud servers. A quantum identity authentication mechanism is introduced to the authenticated user based on a quantum sequence. This protocol enhances the long-term security of the system during the storage phase through threshold distribution and proactive share refreshing mechanisms, and utilizes quantum states to complete the secure reconstruction of secrets during the recovery phase. Additionally, this scheme avoids direct interaction between cloud servers, improving the security in untrusted cloud environments. Security analysis shows that this protocol can effectively resist threats such as external eavesdropping and internal collusion.
Abstract Quantum secret sharing (QSS) plays a crucial role in quantum cryptography as a privacy preserving scheme. Designing an efficient QSS protocol requires addressing three key challenges: 1) dynamic agent membership (handling agents joining or leaving during execution), 2) adversarial resilience (ensuring robustness against dishonest agents), and 3) practical optimization (improving computational and communication efficiency while minimizing implementation cost). In this paper, a verifiable dynamic threshold QSS (VDQSS) protocol with authentication capability is proposed. The protocol employs single particles for both authentication and share distribution, combining homogeneous linear recursion (HLR) with mutually unbiased bases (MUBs) to reconstruct multiple secrets. This approach significantly enhances security while reducing protocol complexity. The correctness and practicality of the protocol are validated through experimental simulations. Analytical results demonstrate its robustness against common attacks, providing reliable security guarantees for quantum communications. Compared to existing QSS protocols, the protocol offers enhanced simplicity and practical applicability.
Abstract Quantum secret sharing (QSS) is a fundamental primitive in quantum cryptography, enabling secure distribution of sensitive information among multiple parties. However, existing protocols often suffer from vulnerabilities such as collusion attacks, uneven share distribution, and protocol failure due to random basis selection. This paper proposes a novel QSS protocol that integrates hash-based measurement basis derivation with decoy photon-enhanced eavesdropping detection. The scheme ensures fair and deterministic secret reconstruction while eliminating the need for entangled states or complex quantum operations, thereby significantly reducing the quantum operational complexity and hardware requirements. The protocol’s correctness, security against both internal and external adversaries, and efficiency in terms of qubit usage, transmission delay, and computational overhead are rigorously analyzed. Notably, the protocol supports dynamic participant management, allowing agents to join or leave securely without re-executing the entire protocol. Comparative analysis demonstrates that the proposed approach outperforms existing QSS protocols across multiple performance metrics. By minimizing quantum resource requirements-such as the elimination of entanglement generation and complex quantum operations-our protocol enhances compatibility with near-term quantum networks, thus facilitating the transition from theoretical QSS models to experimentally feasible implementations.
Abstract Quantum Secret Sharing (QSS) mitigates critical vulnerabilities in classical cryptographic protocols by leveraging quantum mechanics to achieve information-theoretic security. However, existing QSS schemes encounter challenges related to scalability, resistance to collusive attacks, and the lack of robust participant authentication. This paper proposes a novel ( r , m ) threshold QSS protocol that integrates group authentication with quantum–classical hybrid techniques to address these limitations. By incorporating the Quantum Fourier Transform (QFT), Inverse QFT (IQFT), and controlled-U gate operations within a trivariate polynomial secret-sharing framework, the protocol enhances security against intercept-resend, entangle-measure, and collusive attacks while reducing computational overhead. A practical example is provided to validate the protocol’s effectiveness.
The emerging quantum technology has highlighted the necessity for secure and efficient secret sharing in quantum networks. In this paper, we introduce a verifiable multiparty counterfactual quantum secret sharing (QSS) protocol, enhancing security and efficiency. This QSS protocol utilizes a low-depth quantum circuit to encrypt and decrypt information, which comprises a unitary operator constructed using a preshared secret key. To ensure the robustness and verifiability of the shared secret key, the protocol imposes constraints on the participants with the Chinese remainder theorem. The most significant advantage of our proposed QSS protocol is incorporating counterfactual communication, which considerably enhances the scheme’s security by enabling exchange-free information sharing among participants, thereby minimizing the risk of eavesdropping or intercept-and-resend attacks. Furthermore, we incorporate a weighted-threshold mechanism that provides flexibility, enabling diverse use cases to design security protocols for quantum networks. The security analysis of the counterfactual QSS protocol and its implementation on IBM Quantum computers reveals strong resilience to internal and external attacks, along with high efficiency and robustness, making it effective for quantum encryption in the noisy intermediate-scale quantum era.