Baojun Liu (刘保君)

Baojun Liu (刘保君)

Assistant Professor

Baojun Liu (刘保君)

助理教授
FIT 4-204, 清华大学, 北京市海淀区, 100084
(+86) 130~5153~7959
bjliu0 [at] gmail -dot- com (primary)
lbj [at] tsinghua -dot- edu -dot- cn (unreliable)

Headline

主要研究领域：网络基础设施安全、互联网测量与安全分析、涉网犯罪与黑灰产业链对抗
每年大约招收 2 名博士生/硕士生，当前本科三年级或硕士三年级。
欢迎对网络安全感兴趣，对技术充满好奇心，自我驱动力强，编程能力与英语能力优秀的同学与我联系。
实验室同时可对外提供科研助理（工程师）以及客座研究生等岗位，有意者请邮件联系。

About

清华大学，网络科学与网络空间研究院，网络与信息安全实验室（NISL），助理教授。 2020年入选清华大学“水木学者”计划，2022年获得ACM中国计算机安全分会“科技新星奖”。主持十四五装备预研项目、国家自然科学基金项目以及阿里巴巴创新研究计划AIR项目。

面向国家网络安全与国计民生重大战略需求以及世界科技前沿，开展创新性学术研究工作。1）针对互联网关键基础设施以及核心网络协议，多次于国际上率先发现新型未知重大安全风险。研究成果涵盖了域名系统、公钥基础设施及内容分发网络等多个关键领域，影响了互联网标准化组织与主流厂商的安全实践，有力推动了域名加密协议部署应用，向国家相关部委提交专题研究报告，提升了我国关键网络基础设施应对未知风险的能力。基于上述贡献，入选国际互联网治理领域权威机构ICANN根服务器咨询委员会核心专家组成员。2）针对日益猖獗的电信网络诈骗及地下黑灰产活动，同知名安全厂商深度协作，检测违法传播源头并遏制犯罪活动蔓延。研究成果广泛应用于大规模检测伪基站虚假短信、鱼叉式定向欺诈短信、非法流量劫持及广告注入等活动，长期跟踪并刻画犯罪团伙的行为策略，并于我国用户设备终端检出了百万量级的加密通信虚假根证书，证实了大规模用户通信数据正面临着被攻击者操控风险。研究成果对于遏制互联网网络犯罪活动具有重要的现实意义。

学术研究成果取得了一定的国际影响力，多次协助国内外互联网厂商修复高危安全漏洞，累计获得国际信息安全漏洞库近160项编号；累计于网络安全领域竞争最为激烈的四大顶级会议发表高水平论文近20篇，在该领域国内外青年学者之中名列前茅，多次荣获具有重要国际影响力的学术奖项，包括国际互联网协会颁发的网络研究应用奖、网络安全顶级会议NDSS会议杰出论文奖、DSN会议最佳论文奖等。研究成果得到了学术界广泛关注，被ACM TechNews、NewsBreak及Opera News等几十家国际知名媒体及政府机构宣传报道，著名科技媒体The Register将研究成果置于网站封面宣传长达四天。国际知名网络安全专家评价：上述研究成果改善了关键网络基础设施的安全性；在学术界和工业界均产生了显著影响。

研究兴趣

  • 大规模网络流量操控行为检测与分析
  • 互联网域名系统安全与测量
  • 公钥基础设施安全与测量
  • 涉网犯罪与黑灰产业链检测及对抗

教育

  • 加州大学伯克利分校 国际计算机科学研究所 访问学者. 2018-2019. 导师: Vern Paxson (IEEE Fellow).
  • 清华大学 计算机科学与技术系 博士生. 2015-2020. 导师: 刘莹研究员, 段海新教授 Dissertation: Research on Security of Internet Domain Name System.
  • 西安电子科技大学 电子工程学院 本科生. 2011-2015.

职业经历

  • 2022 – 今. 清华大学 网络研究院; 中关村国家实验室，双聘助理教授.
  • 2020 - 2022, 清华大学 网络研究院 博士后（水木学者）

发表国际会议论文

  • Xiang Li, Chaoyi Lu, Baojun Liu, Qifan Zhang, Zhou Li, Haixin Duan and Qi Li. The Maginot Line: Attacking the Boundary of DNS Caching Protection, Proceedings of The 32nd USENIX Security Symposium (USENIX Security), Anaheim, California, USA, August 9-11, 2023.

  • Run Guo, Jianjun Chen, Yihang Wang, Keran Mu, Baojun Liu, Xiang Li, Chao Zhang, Haixin Duan and Jianping Wu. Temporal CDN-Convex Lens: A CDN-Assisted Practical Pulsing DDoS Attack, Proceedings of The 32nd USENIX Security Symposium (USENIX Security), Anaheim, California, USA, August 9-11, 2023.

  • Mingming Zhang, Xiang Li, Baojun Liu, Jianju Lu, Yiming Zhang, Jianjun Chen, Haixin Duan, Shuang Hao and Xiaofeng Zheng. Detecting and Measuring Security Risks of Hosting-Based Dangling Domains, Proceedings of The 2023 ACM SIGMETRICS (ACM SIGMETRICS), Orlando, Florida, USA, June 19-23, 2023.

  • Xiang Li, Baojun Liu, Xuesong Bai, Mingming Zhang, Qifan Zhang, Zhou Li, Haixin Duan and Qi Li. Ghost Domain Reloaded: Vulnerable Links in the Domain Name Delegation and Revocation, Proceedings of The 30th Annual Network and Distributed Security Symposium (NDSS), San Diego, California, USA, 27 February – 3 March, 2023.

  • Mingxuan Liu, Yiming Zhang, Baojun Liu and Haixin Duan. Exploring the Characteristics and Security Risks of Emerging Emoji Domain Names, Proceedings of The 27th European Symposium on Research in Computer Security (ESORICS), Copenhagen, Denmark, September 26-30, 2022.

  • Huikai Xu, Miao Yu, Yanhao Wang, Yue Liu, Qinsheng Hou, Zhenbang Ma, Haixin Duan, Jianwei Zhuge and Baojun Liu. Trampoline Over the Air: Breaking in IoT Devices Through MQTT Brokers, Proceedings of The 7th IEEE European Symposium on Security and Privacy (EuroS&P), Genoa, June 6-10, 2022.

  • Fenglu Zhang, Chaoyi Lu, Baojun Liu, Haixin Duan and Ying Liu. Measuring the Practical Effect of DNS Root Server Instances: A China-Wide Case Study, Proceedings of Passive and Active Measurement Conference (PAM), Virtual event, March 28-30, 2022.

  • Qinge Xie, Shujun Tang, Xiaofeng Zheng, Qingran Lin, Baojun Liu, Haixin Duan and Frank Li. Building an Open, Robust, and Stable Voting-Based Internet Domain Top List, Proceedings of The 31th USENIX Security Symposium (USENIX Security), Boston, MA, USA, August 10-12, 2022.

  • Chuhan Wang, Kaiwen Shen, Minglei Guo, Yuxuan Zhao, Mingming Zhang, Jianjun Chen, Baojun Liu, Xiaofeng Zheng, Haixin Duan, Yanzhong Lin and Qingfeng Pan. A Large-scale and Longitudinal Measurement Study of DKIM Deployment, Proceedings of The 31th USENIX Security Symposium (USENIX Security), Boston, MA, USA, August 10-12, 2022.

  • Xuewei Feng, Qi Li, Kun Sun, Ke Xu, Baojun Liu, Xiaofeng Zheng, Qiushi Yang, Haixin Duan and Zhiyun Qian. PMTUD is not Panacea: Revisiting IP Fragmentation Attacks against TCP, Proceedings of The 29th Annual Network and Distributed Security Symposium (NDSS), San Diego, California, 27 Feruary - 3 March, 2022.

  • Mingxuan Liu, Yiming Zhang, Baojun Liu, Zhou Li, Haixin Duan and Donghong Sun. Detecting and Characterizing SMS Spearphising Attacks, Proceedings of The 37th Annual Computer Security Applications Conference (ACSAC), Austin, Texas, USA, December 6-10, 2021.

  • Yiming Zhang, Baojun Liu, Chaoyi Lu, Zhou Li, Haixin Duan, Jiachen Li and Zaifeng Zhang. Rusted Anchors: A National Client-Side View of Hidden Root CAs in the Web PKI Ecosystem, Proceedings of The 28th ACM Conference on Computer and Communications Security (CCS), Seoul, South Korea, November 15-19, 2021.

  • Xiang Li, Baojun Liu, Xiaofeng Zheng, Haixin Duan, Qi Li and Youjun Huang. Fast IPv6 Network Periphery Discovery and Security Implications, Proceedings of The 51th IEEE/IFIP International Conference on Dependable Systems and Networks (DSN), Virtual, June 21-24, 2021.

  • Chaoyi Lu, Baojun Liu, Yiming Zhang, Zhou Li, Fenglu Zhang, Haixin Duan, Ying Liu, Joann Chen, Jinjin Liang, Zaifeng Zhang, Shuang Hao and Min Yang. From WHOIS to WHOWAS: A Large-Scale Measurement Study of Domain Registration Privacy under the GDPR, Proceedings of The 28th Annual Network and Distributed Security Symposium (NDSS), Virtual, February 21-25, 2021.

  • Kaiwen Shen, Chuhan Wang, Xiaofeng Zheng, Minglei Guo, Chaoyi Lu, Baojun Liu, Yuxuan Zhao, Shuang Hao, Haixin Duan, Qinfeng Pan and Min Yang. Weak Links in Authentication Chains: A Large-scale Analysis of Email Sender Spoofing Attacks, Proceedings of The 30th USENIX Security Symposium (USENIX Security), Vancouver, BC, Canada, August 11-13, 2021.

  • Mingming Zhang, Xiaofeng Zheng, Kaiwen Shen, Ziqiao Kong, Chaoyi Lu, Yu Wang, Haixin Duan, Shuang Hao, Baojun Liu and Min Yang. Talking with Familiar Strangers: An Empirical Study on HTTPS Context Confusion Attacks, Proceedings of The 27th ACM Conference on Computer and Communications Security (CCS), Orlando, USA, November 9-13, 2020.

  • Yiming Zhang, Baojun Liu, Chaoyi Lu, Zhou Li, Haixin Duan, Shuang Hao, Mingxuan Liu, Ying Liu, Dong Wang and Qiang Li. Lies in the Air: Characterizing Fake-base-station Spam Ecosystem in China, Proceedings of The 27th ACM Conference on Computer and Communications Security (CCS), Orlando, USA, November 9-13, 2020.

  • Xiaofeng Zheng, Chaoyi Lu, Jian Peng, Qiushi Yang, Dongjie Zhou, Baojun Liu, Keyu Man, Shuang Hao, Haixin Duan and Zhiyun Qian. Poison over Troubled Forwarders: A Cache Poisoning Attack Targeting DNS Forwarding Devices, Proceedings of The 29th USENIX Security Symposium (USENIX Security), Boston, MA, USA, August 12-14, 2020.

  • Weizhong Li, Kaiwen Shen, Run Guo, Baojun Liu, Jia Zhang, Haixin Duan, Shuang Hao, Xiarun Chen and Yao Wang. CDN Backfired: Amplification Attacks Based on HTTP Range Requests, Proceedings of The 50th IEEE/IFIP International Conference on Dependable Systems and Networks (DSN), Valencia, Spain, June 29 - July 02, 2020.

  • Ruo Guo, Weizhong Li, Baojun Liu, Shuang Hao, Haixin Duan, Jia Zhang, Kaiwen Shen, Jianjun Chen and Ying Liu. CDN Judo: Breaking the CDN DoS Protection with Itself, Proceedings of The 27th ISOC Network and Distributed System Security Symposium (NDSS), Valencia, Spain, June 29 - July 02, 2020.

  • Chaoyi Lu, Baojun Liu, Zhou Li, Shuang Hao, Haixin Duan, Mingming Zhang, Chunying Leng, Ying Liu, Zaifeng Zhang and Jianping Wu. An End-to-End, Large-Scale Measurement of DNS-over-Encryption: How Far Have We Come? Proceedings of The 2019 Internet Measurement Conference (IMC), Amsterdam, Netherlands, October 21-23, 2019.

  • Kun Du, Hao Yang, Zhou Li, Haixin Duan, Shuang Hao, Baojun Liu, Yuxiao Ye, Mingxuan Liu, Xiaodong Su, Guang Liu, Zhifeng Geng, Zaifeng Zhang and Jinjin Liang. TL;DR Hazard: A Comprehensive Study of Levelsquatting Scams, Proceedings of The 15th International Conference on Security and Privacy On Communication Networks (SecureComm), Orlando, USA, October 23-25, 2019.

  • Baojun Liu, Zhou Li, Peiyuan Zong, Chaoyi Lu, Haixin Duan, Ying Liu, Sumayah Alrwais, XiaoFeng Wang, Shuang Hao, Yaoqi Jia, Yiming Zhang, Kai Chen and Zaifeng Zhang. TraffickStop: Detecting and Measuring Illicit Traffic Monetization Through Large-scale DNS Analysis, Proceedings of The 4th IEEE European Symposium on Security and Privacy (IEEE EuroS&P), Stockholm, Sweden, June 17-19, 2019.

  • Eihal Alowaisheq, Peng Wang, Sumayah Alrwais, Xiaojing Liao, XaioFeng Wang, Tasneem Alowaisheq, XiangHang Mi, Siyuan Tang and Baojun Liu. Cracking Wall of Confinement: Understanding and Analyzing Malicious Domain Takedowns, Proceedings of The 26th ISOC Network and Distributed System Security Symposium (NDSS), San Diego, CA, USA, February 24-27, 2020.

  • Xianghang Mi, Xuan Feng, Xiaojing Liao, Baojun Liu, Xiaofeng Wang, Feng Qian, Zhou Li, Sumayah Alrwais, Limin Sun and Ying Liu. Resident Evil: Understanding Residential IP Proxy as a Dark Service, Proceedings of The 40th IEEE Symposium on Security and Privacy (IEEE S&P), San Francisco, USA, May 20-22, 2019.

  • Run Guo, Jianjun Chen, Baojun Liu, Jia Zhang, Chao Zhang, Haixin Duan, Tao Wan, Jian Jiang, Shuang Hao and Yaoqi Jia. Abusing CDNs for Fun and Profit: Security Issues in CDNs’ Origin Validation, Proceedings of The 37th IEEE International Symposium on Reliable Distributed Systems (SRDS), Bahia, Brazil, October 2-5, 2018.

  • Mingming Zhang, Baojun Liu, Chaoyi Lu, Jia Zhang, Shuang Hao and Haixin Duan. Measuring Privacy Threats in China-Wide Mobile Networks, Proceedings of The 8th USENIX Workshop on Free and Open Communications on the Internet (FOCI), Baltimore, USA, August 14, 2018.

  • Baojun Liu, Chaoyi Lu, Haixin Duan, Ying Liu, Zhou Li, Shuang Hao and Min Yang. Who Is Answering My Queries: Understanding and Characterizing Interception of the DNS Resolution Path, Proceedings of The 27th USENIX Security Symposium (USENIX Security), Baltimore, USA, August 14, 2018.

  • Baojun Liu, Chaoyi Lu, Zhou Li, Ying Liu, Haixin Duan, Shuang Hao and Zaifeng Zhang. A Reexamination of Internationalized Domain Names: the Good, the Bad and the Ugly, Proceedings of The 48th IEEE/IFIP International Conference on Dependable Systems and Networks (DSN), Luxembourg City, Luxembourg, June 25-28, 2018.

  • Daiping Liu, Zhou Li, Kun Du, Haining Wang, Baojun Liu and Haixin Duan. Don’t Let One Rotten Apple Spoil the Whole Barrel: Towards Automated Detection of Shadowed Domains, Proceedings of The 24th ACM Conference on Computer and Communications Security (CCS), Dallas, TX, October 30 - November 3, 2017.

教学（课程客座讲师）

  • 清华大学，2021年秋季学期，《网络测量技术》网络测量前沿，研究生，选课人数约15人
  • 清华大学，2020年秋季学期，《网络测量技术》网络测量前沿，研究生，选课人数约15人
  • 清华大学，2020年秋季学期，《下一代互联网》网络安全专题，研究生，选课人数约20人
  • 清华大学，2019年秋季学期，《网络测量技术》网络测量前沿，研究生，选课人数约15人
  • 清华大学，2019年秋季学期，《计算机网络安全技术》域名系统安全专题，研究生，选课人数约30人
  • 清华大学，2019年秋季学期，《下一代互联网》网络安全专题，研究生，选课人数约15人

学术任职与公共服务

  • ICANN 根服务器系统安全与稳定咨询委员会成员
  • 组织安全竞赛：DataCon 大数据安全分析竞赛, Coremail 邮件安全竞赛
  • 期刊论文审稿: IEEE Transactions on Dependable and Securing Computing (TDSC), ACM Transactions on Privacy and Security (TOPS), Computer Networks (CN), ACM Digital Threats: Research and Practice (DTRAP)
  • 会议论文审稿：Network and Distributed System Security Symposium (NDSS), ACM Conference on Computer and Communications Security (CCS), European Symposium on Research in Computer Security (ESORICS), International Conference on Distributed Computing Systems (ICDCS), Annual Computer Security Applications Conference (ACSAC), IEEE/IFIP International Conference on Dependable Systems and Networks (DSN)

奖励与荣誉

  • 2022, ACM中国计算机安全分会“科技新星奖”
  • 2020, 清华大学“水木学者”
  • 2020, 清华大学计算机系优秀博士毕业生
  • 2020, 互联网研究任务组应用网络研究奖（ANRP）
  • 2020, IEEE/IFIP DSN 会议最佳论文奖
  • 2019, NDSS 会议杰出论文奖
  • 2019, ACM IMC 会议最佳论文奖提名、社区贡献奖提名
  • 2019, 第五届下一代互联网创新技术大赛一等奖
  • 2018, 清华大学博士生国家奖学金