Blockchain Technology

Authors: Praveen Raj .K, Mrs . sri Padma

Abstract: Data sharing is increasingly critical across diverse domains—healthcare, IoT, enterprise, supply chains—yet conventional centralised data-sharing frameworks suffer from issues of trust, integrity, access-control, and single points of failure. Blockchain technology offers a promising alternative: via decentralised ledgers, cryptographic immutability, smart contracts and distributed consensus, it can enhance data sharing by improving security, transparency and autonomy. This paper explores a blockchain-based secure data sharing framework: firstly reviewing existing literature and gaps; then presenting an existing model (baseline) and a proposed new architecture that separates data ownership from data storage (on-chain/off-chain), incorporates lightweight cryptography and traceability via non-fungible tokens (NFTs) or S equivalent, and implements fine-grained access control via smart contracts. We describe the modules of the system (data owner module, data requester module, blockchain ledger module, off-chain storage module), outline an implementation prototype, and discuss evaluation in terms of security and performance. We conclude that the proposed framework improves data sharing trust and security while mitigating key limitations of prior systems (storage overhead, single trust authority). We also identify future research directions such as scalability, privacy preservation, cross-chain and regulatory compliance.