区块链隐私保护研究与实践综述

Survey of Research and Practices on Blockchain Privacy Protection

基于区块链的分布式账本集成了非对称加密体系、P2P网络、共识算法、智能合约等多种技术,保证事务记录的一致性和不可篡改性.但是,区块链技术中的账本共享机制也带来了隐私威胁,用户身份、账户地址、交易内容等信息的隐私保护成为研究的关注点.讨论了区块链系统中的隐私威胁;着重分析了地址混淆、信息隐藏、通道隔离等3类隐私保护机制,详细介绍各类机制的原理、模型、特征及实现技术;最后探讨了实际应用中,区块链隐私保护技术在系统性能和可扩展性方面的挑战和发展方向.

Blockchain-based distributed ledger aims to provide consistent and tamper-resistant transaction records by integrating various security technologies such as asymmetric cryptosystem, P2P network, consensus algorithm, and smart contract. However, as each node in the blockchain system shares a copy of the public ledger, such data sharing mechanism also introduces vulnerabilities that hackers could exploit to attack private information. Privacy protection of blockchain systems thus gains wide attentions from researchers. Various techniques have been proposed to protect users’ identity, address, and transaction information from security threats. This study investigates blockchain privacy threats. It made a comprehensive survey of state-of-the-art privacy protection technologies which are categorized into three mechanisms including address confusion, information hiding, and channel isolation. The paper introduces the principles, models, and various implementations of each mechanism. It finally discusses the challenges of performance and scalability in practice and future technology advancement directions.