PRIVACY-ENHANCED REDACTABLE BLOCKCHAIN WITH CONTROLLED ACCESS IN DECENTRALIZED ENVIRONMENTS

Abstract

In recent years, redactable blockchain has emerged as a promising technology, offering decentralization, traceability, and transparency while allowing authorized modifications to on-chain data. Despite its advantages, current redactable blockchain systems face challenges such as data privacy breaches and excessive communication overhead, limiting their practical application. To address these issues, this paper introduces PriChain, a privacypreserving and fine-grained redactable blockchain framework designed for decentralized environments. PriChain empowers data owners with the ability to control who can access and modify their onchain data, ensuring that only authorized users can perform redaction while preserving data confidentiality. By leveraging multiauthority attribute-based encryption, PriChain enables precise access control and ensures resistance to unauthorized collaboration or collusion. The framework significantly reduces communication and storage overhead compared to conventional methods. Security analysis confirms that PriChain is resilient against chosen-plaintext attacks, making it a robust and practical solution for privacy-focused blockchain applications.