DARB: Decentralized, Accountable and Redactable Blockchain for Data Management

Blockchain technology, known for its immutable distributed ledger, which greatly improves the credibility of data management in various applications. However, the immutability may result in erroneous data being permanently stored in the blockchain, affecting the security of the blockchain system. To address this issue, redactable blockchain is proposed to allow flexibly modifications of erroneous data in blockchain. Despite their promise, current redactable blockchain solutions often fall short in balancing two critical aspects: decentralization and data accountability. In this paper, we propose a Decentralized, Accountable and Redactable Blockchain solution (DARB). Our solution aims to mitigate the risks associated with central authority while ensuring secure accountability in data modification processes. Decentralization is achieved by using authorized authorities instead of the central authority, utilizing decentralized ciphertext policy attribute-based encryption. Additionally, it incorporates traceable ring signatures, which enable the authorized authorities to collaborate effectively in holding edited data accountable and tracing the identity of malicious modifiers. The security analysis and experimental results demonstrate that the DARB scheme successfully facilitates secure data rewriting and ensures accountability, all while maintaining an acceptable level of additional time overhead.