A Blockchain-based Certificable and Redactable E-taxing Protocol

Taxation is a primary source for the government revenue, and its complexity of the tax administration creates loopholes that can be exploited by dishonest taxpayers to minimize the tax paid to the government. We utilize the blockchain technology to create a transparent and secure tax system as well as to simplify the process of administering taxes. However, due to the decentralized and untamperable nature of blockchain may have limitations in tax system applications. In this paper, we propose a blockchain-based certificable and redactable scheme for e-tax. We adopt self-certified public keys to authenticate taxpayers and chameleon hash function to delete (merge) the tax information of related users on the blockchain while keeping the block header unchanged.