Attribute-Based Policy-Hiding Redactable Blockchain With Authorizable Verification for Energy Internet

The goal of the energy internet is to enable communication between distributed energy endpoints to facilitate information exchange and trading matching. Blockchain, which ensures content consistency, bridges the gaps between multiple energy stakeholders and satisfies the need for universal trust. However, applying blockchain directly in peer-to-peer trading can result in the permanent inclusion of illegal or outdated data in blockchain databases, hindering efficient interaction. Driven by emerging application requirements and legal regulations, redactable blockchain (EuroS&P 2017) was introduced, allowing the block history to be rewritten via collisions in chameleon hash functions (CHFs). Nevertheless, current solutions still face challenges, including trapdoor security risks, privacy leakage, and indefinite redactions. This article presents a redactable energy blockchain scheme (REBS) with partially attribute-based policy hiding, which enables controlled multiauthority key generation and redactor attribute verification. To prevent the abuse of redaction permission, REBS employs time-updatable CHFs for redaction. Additionally, we design a delegation algorithm that adds dynamic flexibility to attribute verification nodes, permitting them to delegate key share distribution authority to other nodes on demand. The detailed security proofs and performance evaluations demonstrate the feasibility of REBS.