BC-QRSDS: A Blockchain-Cloud Quantum-Resilient Algorithmfor Secure Group Data Sharing

Abstract

Large-scale storage and sharing of general digital data has been made possible by the quick
development of cloud computing; yet, centralised cloud settings confront serious issues with
data confidentiality, key management, unwanted access, and new dangers from quantum
computing. In order to securely and effectively share general data among authorized users,
this study suggests a Blockchain-Cloud Quantum-Resilient Secure Data Sharing Algorithm
(BC-QRSDS). The suggested method combines the CRYSTALS-Kyber post-quantum
cryptography mechanism, cloud storage, and blockchain-based decentralized authorization
into a single safe data-sharing framework. While blockchain smart contracts oversee user
permissions, group-sharing policies, access verification, and tamper-resistant data-sharing
transactions, BC-QRSDS encrypts data using session-based cryptographic keys and stores it
as ciphertext in the cloud. While Kyber-based key setup offers defense against quantumenabled
assaults during secure key exchange, the suggested technique facilitates regulated
individual, group, and subgroup data sharing. By generating session-specific cryptographic
data for approved sharing procedures and maintaining a single long-term private key for each
user, an effective key-management system minimizes the need for duplicated key distribution
and storage. Two secure data-sharing techniques that are currently in use are empirically
compared with the proposed approach utilizing different user counts and data-sharing
requests. Time complexity, key generation time, encryption time, decryption time, key
management overhead, communication overhead, blockchain transaction latency, access
verification time, and storage overhead are all taken into account in the evaluation. The
suggested BC-QRSDS approach's computational and scalability features, as well as its
applicability for safe, decentralized, and quantum-resilient cloud-based data sharing, are
demonstrated by the experimental study.