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 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.
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 In the field of quantum cryptography, Quantum Secret Sharing (QSS) holds substantial importance, with identity authentication emerging as a key strategy for safeguarding information. It efficiently certifies the identification of both persons involved in the conversation, which contributes to increased security measures. Our proposal, a (m, n) threshold Quantum Secret Sharing (QSS) scheme introduces a unique approach to mutual identity authentication, utilizing mutually unbiased bases. During the secret recovery phase, the scheme ensures that secrets exclusively held by participants remain undisclosed and are not transmitted, reinforcing the security of the communication process. As a result, external eavesdroppers are left empty-handed in their attempt to access information about secrets during this phase. Our protocol surpasses in terms of security, effectiveness, and practicality, proving its resilience against intercept–resend attacks, collusion attacks, collective attacks, and forgery attacks according to a comprehensive security analysis.
Quantum secret sharing (QSS) is an important branch of quantum cryptography. Identity authentication is a significant means to achieve information protection, which can effectively confirm the identity information of both communication parties. Due to the importance of information security, more and more communications require identity authentication. We propose a d-level (t,n) threshold QSS scheme in which both sides of the communication use mutually unbiased bases for mutual identity authentication. In the secret recovery phase, the sharing of secrets that only the participant holds will not be disclosed or transmitted. Therefore, external eavesdroppers will not get any information about secrets at this phase. This protocol is more secure, effective, and practical. Security analysis shows that this scheme can effectively resist intercept–resend attacks, entangle–measure attacks, collusion attacks, and forgery attacks.
Abstract The ( t , n ) -threshold schemes offer significant advantages over n , n -threshold schemes due to their flexibility, fault tolerance, and practicality. In this paper, a ( t , n ) -threshold quantum secret-sharing (QSS) and quantum state sharing schemes based on single photons are proposed by incorporating unitary phase shift operations. The proposed scheme employs symmetric bivariate polynomials and utilizes polynomial interpolation for secret sharing. This approach facilitates the secure distribution of classical data and quantum states while maintaining confidentiality and integrity during transmission. Mutual identity authentication between the dealer and participants is ensured, and the accuracy of secret reconstruction is achieved using Lagrange interpolation. The analysis demonstrates that the proposed scheme is resilient against common interception methods, including eavesdropping attacks and participant-driven threats such as entanglement swapping. Additionally, the scheme is characterized by ease of implementation within physical frameworks and adaptability to various applications offering a practical and efficient alternative to existing methods.
Verifiable secret sharing schemes are important in cloud computing environments. Thus a key can be distributed over many servers by threshold secret sharing mechanism. The key is then reconstructed when needed. Secret sharing has also been suggested for sensor networks where the links are liable to be tapped by sending the data in shares which makes the task of the eavesdropper harder. The security in such environments can be made greater by continuous changing of the way the shares are constructed. In the present paper we proposed a verifiable quantum -threshold secret sharing scheme using Lagrange interpolation and two qudit Bell state in -dimensional Hilbert space. As discussed in the second last section of this paper, the proposed scheme is enough secure against the fraud in secret share distribution phase as well as secret reconstruction phase.
Distributed storage plays an essential role in realizing robust and secure data storage in a network over long periods of time. A distributed storage system consists of a data owner machine, multiple storage servers and channels to link them. In such a system, secret sharing scheme is widely adopted, in which secret data are split into multiple pieces and stored in each server. To reconstruct them, the data owner should gather plural pieces. Shamir's (k, n)-threshold scheme, in which the data are split into n pieces (shares) for storage and at least k pieces of them must be gathered for reconstruction, furnishes information theoretic security, that is, even if attackers could collect shares of less than the threshold k, they cannot get any information about the data, even with unlimited computing power. Behind this scenario, however, assumed is that data transmission and authentication must be perfectly secure, which is not trivial in practice. Here we propose a totally information theoretically secure distributed storage system based on a user-friendly single-password-authenticated secret sharing scheme and secure transmission using quantum key distribution, and demonstrate it in the Tokyo metropolitan area.