Fine-Grained Redactable Blockchain Using Trapdoor-Hash

Abstract

The blockchains immutability permits widespread application in untrusted contexts such as digital currency, the Internet of Things, and anti-counterfeiting. This functionality, however, presents difficulties for regulators, developers, and users. For instance, unsuitable data may be permanently retained, blockchains may breach applicable rules and regulations, and smart contracts may contain bugs. To elegantly address a series of issues arising from the immutability of the blockchain, we propose a redactable blockchain that utilizes trapdoor-hash to repair harmful data in the blockchain, allowing for efficient transaction editing, deletion, and smart contract repair without destroying the blockchain structure or security features. Additionally, our solution provides fine-grained control over modification authority, allowing the user to change the transaction he initiated and the regulators to delete the erroneous transaction. Finally, we integrate and test the suggested technique with one of the most influential enterprise-grade permissioned blockchain platforms, Hyperledger Fabric. The results demonstrate that our technique has a low overhead when compared to an immutable blockchain. As compared to other existing redactable blockchains, our technique provides greater permission control flexibility without sacrificing efficiency or performance.