An Overview of Privacy-preserving Technologies in Blockchain

Blockchain technology, with its decentralization as well as tamper-proof characteristics, has achieved wide application in major fields in recent years. However, because of the potential of privacy leakage that comes with its transparency, privacy protection technology has emerged as a key area of current blockchain research. The first step involves reviewing the blockchain's architecture and selecting a summary of the privacy threats posed by the four layers of the blockchain: data, network, transaction, and application. Next, it concentrates on describing the two more significant types of blockchain privacy protection technology: zero-knowledge proof and homomorphic encryption. The former is developed from its fundamental ideas, application scenarios in the blockchain, and performance and security analysis. Conversely, zero-knowledge proof is derived from three from three aspects of its basic concept, application in blockchain, and technical challenges; finally, the privacy protection technology in blockchain is summarized and a prediction of its future research direction development is made.