A Survey on Zero-Knowledge Proof in Blockchain

Blockchain, which is usually regarded as a public, decentralized and distributed ledger, has attracted significant attention recently. In the environment of blockchain, all historical transaction data are recorded and stored. However, because blockchain is open and transparent, a malicious user may illegally access private transaction data, including transaction amount, account address, and account balance. As a cryptographic technique, zero-knowledge proof (ZKP) can be used to verify whether the prover has enough transaction amount in the environment of blockchain without leaking any private transaction data. This article provides a comprehensive survey on ZKP in the environment of blockchain with the aim of highlighting security problems and challenges. It first discusses the framework, models and applications of ZKP. Next, it provides an introduction of blockchain, and proposes a framework of ZKP in the environment of blockchain. Then, it highlights the current state of ZKP in the environment of blockchain. Finally, it identifies some potential problems and future research directions.