Data Privacy-Preserving for Blockchain: State of the Art and Trends

As a distributed ledger, blockchain solves the decentralized trust problem by integrating a series of techniques such as distributed consensus, P2P (Peer to Peer) network, smart contracts, and cryptography. Blockchain has a meaningful impact on the society and lifts a bloom of researches and applications due to the characteristics of immutability and decentralization. Blockchain technology has a broad scope of applications, and its unique advantages can deal with the pain points in many industry scenarios. However, the blockchain technology is faced with the problem of data privacy leakage in its applications, such as the disclosure of transaction, account and personal information privacy, which greatly impose restrictions on the application scope and fields. Data privacy-preserving for blockchain has become one of the key problems concerned by researchers. In this survey, we first describe the evolutionary history of blockchain technology, define the concept of corresponding privacy according to applications in the field of blockchain and introduce the main technical points and the technology architecture of blockchain. Then we summarize the privacy-preserving problems faced by the blockchain technology and explore the existing solutions based on the proposed concept of data privacy protection. Finally, some problems that still need to be addressed and future research directions of data privacy-preserving for blockchain are discussed based on the analysis.