SECURING DATA PRIVACY IN PERMISSIONED BLOCKCHAIN NETWORKS USING IDENTITY-BASED ENCRYPTION

Abstract

Permissioned blockchain architectures provide a robust foundation for controlled data sharing among verified participants, yet ensuring payload confidentiality within such networks poses persistent challenges. This paper proposes a framework that integrates Identity-Based Encryption (IBE) with Ethereum smart contracts and the Inter Planetary File System (IPFS) to achieve fine-grained, identity-anchored access control. By using each user's unique identifier as the cryptographic public key, the system eliminates the certificate management overhead inherent in traditional Public Key Infrastructure while maintaining strong data privacy guarantees. A fully functional prototype was implemented in Python and Solidity, demonstrating that only explicitly authorized recipients can decrypt stored messages while non-authorized parties are systematically excluded. Evaluation results confirm system correctness, data integrity, and practical feasibility for enterprise non-transactional data sharing scenarios.