面向联盟链的隐私保护技术综述

Overview of privacy protection technology for consortium blockchain

区块链通过账本数据公开和计算透明来为上层应用提供可信服务,但公开透明的特性容易造成敏感信息泄露,阻碍区块链的发展,隐私保护技术由此成为了研究热点。与公有链不同,联盟链通过权限管理机制完成对网络层和存储层数据的安全隔离,实现外部入侵防御。然而,权限控制不支持用户的身份匿名,无法隐藏交易过程中金额等敏感信息,因此,现有联盟链平台通过嵌入密码功能模块和可信硬件来增强自身的隐私保护能力。该文调研了联盟链面临的隐私泄露风险;分析Hyperledger Fabric、FISCO BCOS和ChainMaker等3个国内外主流联盟链平台中涉及的权限控制、密码技术和可信执行环境,从能否支持身份匿名、交易内容隐藏和隐私计算角度出发,对比平台的隐私保护能力;指出了面向联盟链的隐私保护技术的研究方向。

Blockchain provides trusted services via ledger disclosure and computational transparency,but the openness and transparency features are easy to cause the leakage of sensitive information,which hinders the development of blockchain.Privacy protection technology has become a research hotspot.Different from the public blockchain,consortium blockchain achieves security isolation of network layer and storage layer data via the authority management mechanism to achieve external intrusion prevention.However,permission control does not support the anonymity of users’identities,and cannot hide amounts of information during the transaction process.Therefore,the existing consortium blockchain platform enhances its privacy protection capabilities by embedding the cryptography function module and trusted hardware.Firstly,this paper investigates the privacy leakage risk faced by the consortium blockchain.Secondly,this paper compares and analyzes the privacy protection technologies involved in the three mainstream consortium blockchain platforms,Hyperledger Fabric,FISCO BCOS and ChainMaker,and compares the privacy protection capabilities of platforms from the perspective of whether it can support identity anonymity,transaction hiding and privacy computing.Finally,this paper points out the research direction of privacy protection technology for consortium blockchain.