Smart Contract-Driven Consent Management for Personal Data Sharing

Abstract

The rapid expansion of digital platforms, electronic health systems, IoT devices, and cross-organisational data-sharing environments have resulted in the exchanged amount and sensitivity of personal data growing. Conventional consent management models are centralised, non-transparent, and hard to audit, exposing threats of unauthorised distribution, poor interoperability, and substandard compliance with regulations. Traditional systems have a hard time delivering dynamic, fine-grained and verifiable user control over consent. They do not have transparent audit trails, do not support the use of multi-party authorization, and do not impose the use of data in a manner specific to purpose, particularly when regulated by laws like GDPR. The issue of scalability, the absence of automation, and immutable logging also contribute to the growth of trust and security concerns. The objective of the research is to assess in a critical manner the concept of blockchain-based and smart contract-based consent management models to determine the architectural designs, performance aspects, cryptographic techniques, and compliance measures that enhance personal data control within healthcare, fitness tracking, and wider data-sharing systems. Solution: This paper summarises the evidence regarding the benefits of hybrid on-chain/off-chain architectures, purpose-based access control, threshold cryptography, pseudonymization layers, and business-process-sensitive workflows in improving the transparency, auditability, and automation of consent management through the analytical review of nineteen blockchain-based consent systems. Smart contract systems give enforceability of rules, minimise risk of breach and enhance precision of consent revocation. The remaining issues are scalability, fluctuations in the cost of gas, GDPR-compatible deletion, and multidimensional approval. In general, consent systems based on smart contracts provide a technically plausible and legally consistent platform on which to build the systems of personal data-sharing in the future.