A SCALABLE BLOCKCHAIN FRAMEWORK FOR PRIVACYPRESERVING PERSONAL DATA SHARING AND ACCESS CONTROL

Abstract

The rapid growth of digital services, cloud computing, Internet of Things (IoT) devices, and online platforms has resulted in an unprecedented volume of personal data being generated, stored, and exchanged across distributed environments. While data sharing facilitates innovation and service personalization, it also raises significant concerns regarding privacy, security, unauthorized access, and data misuse. Conventional centralized data management systems often suffer from single points of failure, limited transparency, and vulnerability to cyberattacks, making them inadequate for protecting sensitive personal information in modern digital ecosystems. This paper proposes a Scalable Blockchain Framework for Privacy-Preserving Personal Data Sharing and Access Control that leverages the decentralized and immutable nature of blockchain technology to enhance data security, transparency, and user control. The proposed framework integrates blockchain-based distributed ledgers with fine-grained access control mechanisms and cryptographic techniques to ensure secure and privacy-aware data sharing among authorized entities. Smart contracts are utilized to automate access authorization, policy enforcement, and auditability, thereby eliminating reliance on centralized intermediaries and improving trust among participants. To address scalability challenges commonly associated with blockchain networks, the framework incorporates lightweight consensus mechanisms, off-chain storage solutions, and efficient data indexing strategies that reduce computational overhead and transaction latency. Furthermore, advanced encryption and privacypreserving protocols are employed to safeguard sensitive user information while enabling controlled access based on predefined permissions and user-defined policies. The architecture supports dynamic access management, secure data ownership verification, and transparent tracking of data-sharing activities. Experimental evaluation demonstrates that the proposed framework achieves improved scalability, reduced access latency, enhanced security, and stronger privacy protection compared with traditional centralized and existing blockchain-based data-sharing approaches. The results indicate that the framework effectively balances security, privacy, and performance requirements, making it suitable for healthcare, smart cities, financial services, IoT ecosystems, and other data-intensive applications requiring secure personal data management.