Quantum secret sharing protects distributed quantum information against unauthorized reconstruction, yet existing schemes provide no intrinsic accountability when shares are leaked or forged. This missing capability is particularly relevant in realistic distributed settings, where compromised participants may either expose valid shares or maliciously interfere with reconstruction. Here we establish a framework for traceable quantum secret sharing under these two threat models. We introduce leakage-verifiable and traceable quantum secret sharing (LVT-QSS), which attributes leaked shares through an explicit leakage verification mechanism, and malicious-traceable and accountable quantum secret sharing (MTA-QSS), which identifies participants who submit forged shares during reconstruction. We formulate security definitions for both settings and prove that the proposed protocols satisfy the corresponding guarantees against the relevant adversaries. Numerical simulations under per-share depolarizing noise further quantify the robustness of the proposed schemes and identify verification as the dominant noise sensitive stage. These results incorporate accountability into quantum secret sharing and provide a foundation for traceable distributed quantum cryptography.
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Quantum secret sharing protects distributed quantum information against unauthorized reconstruction, yet existing schemes provide no intrinsic accountability when shares are leaked or forged. This missing capability is particularly relevant in realistic distributed settings, where compromised participants may either expose valid shares or maliciously interfere with reconstruction. Here we establish a framework for traceable quantum secret sharing under these two threat models. We introduce leakage-verifiable and traceable quantum secret sharing (LVT-QSS), which attributes leaked shares through an explicit leakage verification mechanism, and malicious-traceable and accountable quantum secret sharing (MTA-QSS), which identifies participants who submit forged shares during reconstruction. We formulate security definitions for both settings and prove that the proposed protocols satisfy the corresponding guarantees against the relevant adversaries. Numerical simulations under per-share depolarizing noise further quantify the robustness of the proposed schemes and identify verification as the dominant noise sensitive stage. These results incorporate accountability into quantum secret sharing and provide a foundation for traceable distributed quantum cryptography.
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.
The security of a secret sharing protocol is compromised if one or more dishonest participants can reconstruct the secret by deviating from the prescribed protocol, particularly when such malicious behavior remains undetected. Semi-Quantum Secret Sharing (SQSS) is a variant of secret sharing in which the participants possess only classical capabilities, such as preparing and measuring qubits in the computational (Z) basis, while a quantum-capable third party assists the dealer in generating and distributing quantum shares of a classical secret. The limited quantum capabilities of the participants in SQSS protocols may introduce vulnerabilities to collusion attacks, enabling an assisting quantum third party, in collaboration with a dishonest classical participant, to jointly recover the secret even without detection. In this work, we propose a novel SQSS protocol that eliminates this vulnerability and achieves information-theoretic security against collusion attacks. We further prove that the proposed protocol is secure against a broad class of external and internal attacks. Finally, a comparative analysis demonstrates that our construction advances existing SQSS protocols by simultaneously optimizing qubit efficiency, involves a classical dealer, and resilience against DCNA attacks using basic Bell states.
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.
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.
Quantum secret sharing (QSS) is a cryptographic protocol that utilizes fundamental principles of quantum mechanics to securely distribute and reconstruct secret information among multiple participants. Most existing protocols rely on entangled states (such as Bell and GHZ states), but in practical applications. The preparation of entangled state is constrained by a short quantum coherence time, low state fidelity, etc., which makes it difficult to implement entangled resource-dependent QSS protocols. In this work, a novel practical and verifiable multi-party QSS protocol is proposed based on orthogonal product states, which are easier to prepare than entangled states. During the protocol preparation stage, the secret distributor first converts pre-shared classical secret information into the corresponding orthogonal product states according to the encoding rules, and pre-shares a communication key with participants via quantum key distribution (QKD), which is used to hide the initial quantum sequence information through subsequent particle transformation operations. After preparing the orthogonal product states, the distributor reorganizes the particles by position, extracting particles at the same position from each state to form new sequences, shuffling their order, then applying Hadamard operations using a pre-shared key, inserting decoy particles, and sending the sequences to the participants. After receiving it, participants conduct eavesdropping detection, use the same key for the inverse transformations, retain one particle from each sequence, and sequentially pass the remaining particles until the last participant receives a complete set, triggering state verification with the arbiter distributor. If the verification is successful, the particles will be returned to the first participant and the return stage will follow the same procedure. Only after both the transmission and return stage verifications have passed, will the distributor reveal the initial particle positions, allowing participants to collaboratively reconstruct the secret. In the protocol, the secret distributor acts as an arbitrator to verify the particle state information together with participants at designated points (the end of the transmission stage and the end of the return stage) in order to determine whether the particle-state information is error-free during transmission. If the verification fails at either stage, the protocol will be terminated immediately. Meanwhile, considering that the number of participants may change during the execution of the protocol, a dynamic scheme for personnel changes is designed to ensure the flexibility of the protocol. Through the analysis of possible internal and external attacks, It can be proven that our protocol can effectively resist the existing common attack. Using Qiskit simulation experiments, the core quantum procedures of the protocol can be successfully modeled. The experimental results provide strong computational validation of the theoretical feasibility of the protocol.
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. In this paper, we propose a novel QSS protocol that integrates hash-based measurement basis derivation with decoy photon-enhanced eavesdropping detection. Our scheme ensures fair and deterministic secret reconstruction while eliminating the need for entangled states or complex quantum operations. We rigorously analyze the protocol's correctness, security against both internal and external adversaries, and efficiency in terms of qubit usage, transmission delay, and computational overhead. Notably, our protocol supports dynamic participant management, allowing agents to join or leave securely without re-executing the entire protocol. Comparative analysis demonstrates that our approach outperforms existing QSS protocols across multiple performance metrics. This work bridges the gap between theoretical robustness and practical deployment, offering a scalable and resilient solution for post-quantum secure communication.