The immutability of blockchain technology, while fundamental to its trustworthiness, introduces significant challenges for dynamic data governance scenarios such as financial transaction corrections, privacy-preserving healthcare data updates, and GDPR compliance. Existing blockchain rewriting schemes based on chameleon hash techniques alleviate some of these issues but suffer from inherent limitations, including complex key management overhead, lack of regulatory mechanisms, and inflexible access policy enforcement. This paper introduces a chameleon hash that supports the identity update, called IDCHU , which is a novel cryptographic primitive integrating identity-based proxy re-encryption and chameleon hash with ephemeral trapdoors to enable secure, traceable and identity-aware data modifications while supporting flexible user identity updates. The proposed regulable blockchain rewriting scheme built upon IDCHU algorithm ensures compliance through three core mechanisms: identity-bound modification authority, time-constrained modification and cryptographic traceability recorded on a regulatory blockchain. We provide formal security proofs for both the IDCHU algorithm and the blockchain rewriting scheme. The experimental evaluations and comparisons validate the scheme’s efficiency, showcasing its practical viability for real-world applications.
Zhang et al. (Mon,) studied this question.