Accountable Fine-grained Blockchain Rewriting in the Permissionless Setting

TL;DR

This paper introduces an accountable, fine-grained blockchain rewriting framework suitable for permissionless blockchains, enabling secure, trustless modifications with accountability for malicious actions, and demonstrates its practicality through implementation and evaluation.

Contribution

It presents a novel framework for accountable blockchain rewriting in permissionless settings, including an instantiation and practical implementation.

Findings

Framework enhances security and accountability in blockchain rewriting.

Prototype implementation integrates with open blockchains effectively.

Evaluation confirms practicality and efficiency of the proposed approach.

Abstract

Blockchain rewriting with fine-grained access control allows a user to create a transaction associated with a set of attributes, while another user (or modifier) who possesses enough rewriting privileges from a trusted authority satisfying the attribute set can rewrite the transaction. However, it lacks accountability and is not designed for open blockchains that require no trust assumptions. In this work, we introduce accountable fine-grained blockchain rewriting in a permissionless setting. The property of accountability allows the modifier's identity and her rewriting privileges to be held accountable for the modified transactions in case of malicious rewriting (e.g., modify the registered content from good to bad). We first present a generic framework to secure blockchain rewriting in the permissionless setting. Second, we present an instantiation of our approach and show its practicality through evaluation analysis. Last, we demonstrate that our proof-of-concept implementation can be effectively integrated into open blockchains.