  Redactable blockchains allow modifiers or voting committees with modification
privileges to edit the data on the chain. Trapdoor holders in chameleon-based
hash redactable blockchains can quickly compute hash collisions for arbitrary
data, and without breaking the link of the hash-chain. However, chameleon-based
hash redactable blockchain schemes have difficulty solving the problem of
multi-level editing requests and competing for modification privileges. In this
paper, we propose CDEdit, a highly applicable redactable blockchain with
controllable editing privilege and diversified editing types. The proposed
scheme increases the cost of invalid or malicious requests by paying the
deposit on each edit request. At the same time, the editing privilege is
subdivided into request, modification, and verification privileges, and the
modification privilege token is distributed efficiently to prevent the abuse of
the modification privilege and collusion attacks. We use chameleon hashes with
ephemeral trapdoor (CHET) and ciphertext policy attribute-based encryption
(CP-ABE) to implement two editing types of transaction-level and block-level,
and present a practical instantiation and security analysis. Finally, the
implementation and evaluation show that our scheme only costs low-performance
overhead and is suitable for multi-level editing requests and modification
privilege competition scenarios.
