Abstract: As a cornerstone to build a low-cost trusted channel so as to achieve value interconnection,blockchain has been especially highlighted and intensive research has been conducted in recent years.Among other issues within blockchain,challenges on security,privacy,and performance have attracted most eyes.To pave the way to deal with the above challenges,a review of research particularly on blockchain security,privacy and performance issues was presented from the perspectives of technical principle,progress and mechanism.With understanding of blockchain hierarchy and operation principles,the security issues within the layers of peer-to-peer network,consensus mechanism and smart contract were analyzed,and the effectiveness of respective defence measures was evaluated.By analysing the threats to blockchain privacy,the various privacy-protection solutions were evaluated for different protection targets.By identifying the performance related factors,the state-of-the-art solutions on the on-chain and off-chain scaling techniques were discussed.To tackle the existing problems in security,privacy and performance,the possible solutions and directions of future research were proposed respectively.

Key words: blockchain techniques, security, privacy, performance

摘要： 作为构建低成本信任通道、实现价值互联的关键技术,区块链研究在近几年急剧涌现,其中安全、隐私与性能成为最受关注的问题。为助益破解挑战,从问题分析、技术进展与作用机制视角针对区块链安全、隐私与性能问题展开综述,包括:①基于区块链层次结构与运行原理,就对等网络、共识机制和智能合约层面的安全问题及攻防措施进行分析评估;②基于区块链隐私威胁基本原理,比较分析不同隐私保护对象的分级隐私保护策略;③通过分析性能制约因素,评估基于链上与链下两种扩容路线的最新研究进展。此外,针对安全、隐私与性能的现存问题,分别提出可能的解决思路并指出未来研究方向。

关键词: 区块链技术, 安全, 隐私, 性能