QUANTUM SECRET SHARING PROTOCOL SECURITY IN CLOUD ENVIRONMENT

Quantum Secret Sharing (QSS) is a fundamental cryptographic primitive that distributes a secret among multiple participants using quantum information, ensuring that only authorized subsets can reconstruct the original secret. Conventional QSS protocols rely on fixed network topologies and require full participation of all shareholders, introducing significant limitations in scalability, flexibility, and resilience against adversarial threats. This paper proposes a novel QSS framework built upon a generic distributed quantum network adopting a threshold-based (t, n) scheme, permitting any t out of n players to collaboratively reconstruct the secret. The proposed protocol integrates a custom weighting system and a quantum variant of Dijkstra’s algorithm to dynamically select the optimal subset of participants, enhancing routing efficiency and overall system performance. To strengthen user authentication and provide identity obfuscation against both classical and quantum adversaries, CRYSTALS-Kyber post-quantum cryptographic primitives are incorporated alongside SHA-256 hashing. The system architecture adopts a three-tier model comprising a client layer, a processing layer governed by a Central Authority, and a data/security layer with quantum-encrypted storage. Comprehensive security analysis demonstrates compliance with the extended CIA triad and resilience against eavesdropping, impersonation, and collusion attacks. Simulation results confirm that the proposed protocol outperforms traditional QSS models, achieving improved fault tolerance, authentication security, and practical deployability in cloud-based distributed environments.