I am currently an associate professor in School of Mathematics and Statistics, Nanjing University of Science and Technology. My research interest includes information security, cryptography with recent focus on encrypted search and quantum-proof cryptography. I have published more than 40 more papers data security papers with total , including ACM CCS, VLDB, USENIX NDSI, IEEE INFOCOM, ACM ASIACCS, IEEE Transactions on Dependable and Secure Computing, IEEE Transactions on Information Forensics and Security, IEEE Transactions on Services Computing and so on.

🔥 News

• 2024.08:  🎉🎉 Our application for 2024 Jiangsu Provincial Young Science and Technology Talent Support Program (江苏省青年科技人才托举工程资助对象) was approved. Congratulations to Lei!
• 2024.05:  🎉🎉 Our paper “SWAT: A System-Wide Approach to Tunable Leakage Mitigation in Encrypted Data Stores” was accepted by VLDB 2024. Congratulations to Leqian！

📝 Selected Publications

Conference Papers

• SWAT: A System-Wide Approach to Tunable Leakage Mitigation in Encrypted Data Stores
  Leqian Zheng, Lei Xu, Cong Wang, Sheng Wang, Yuke Hu, Zhan Qin, Feifei Li, Kui Ren
  In Proc. of the 50th International Conference on Very Large Databases (VLDB’24), 2024

• HiddenTor: Toward a User-Centric and Private Query System for Tor BridgeDB
  Yichen Zang, Chengjun Cai, Wentao Dong, Lei Xu, Cong Wang
  In Proc. of the 2024 IEEE 44th International Conference on Distributed Computing Systems (ICDCS), 2024

• Leakage-Abuse Attacks Against Forward and Backward Private Searchable Symmetric Encryption
  Lei Xu, Leqian Zheng, Chengzhi Xu, Xingliang Yuan, and Cong Wang
  In Proc. of the 30th ACM Conference on Computer and Communications Security (CCS’23), 2023

• Boomerang: Metadata-Private Messaging under Hardware Trust
  Peipei Jiang, Qian Wang, Jianhao Cheng, Cong Wang, Lei Xu, Xinyu Wang, Yihao Wu, Xiaoyuan Li, and Kui Ren
  In Proc. of the 20th USENIX Symposium on Networked Systems Design and Implementation (NSDI’23), 2023

• The Right to be Forgotten in Federated Learning: An Efficient Realization with Rapid Retraining
  Yi Liu, Lei Xu, Xingliang Yuan, Cong Wang, Bo Li
  In Proc. of the 41st International Conference on Computer Communication (INFOCOM’22), 2022

• EncELC: Hardening and Enriching Ethereum Light Clients with Trusted Enclaves
  Chengjun Cai, Lei Xu, Anxin Zhou, Ruochen Wang, Cong Wang, Qian Wang
  In Proc. of the 39th International Conference on Computer Communication (INFOCOM’20), 2020

• Hardening Database Padding for Searchable Encryption
  Lei Xu, Xingliang Yuan, Cong Wang, Qian Wang, Chungen Xu
  In Proc. of the 38th International Conference on Computer Communication (INFOCOM’19), 2019

• Multi-Writer Searchable Encryption: An LWE-based Realization and Implementation
  Lei Xu, Xingliang Yuan, Ron Steinfeld, Cong Wang, and Chungen Xu
  In Proc. of the 14th ACM ASIA Conference on Computer and Communications Security (AsiaCCS’19), 2019.

Journal Papers

• Sketch-based Adaptive Communication Optimization in Federated Learning
  Pan Zhang, Lei Xu*, Lin Mei, Chungen Xu*
  IEEE Transactions on Computers (TC), 2024

• Toward Full Accounting for Leakage Exploitation and Mitigation in Dynamic Encrypted Databases
  Lei Xu, Anxin Zhou, Huayi Duan, Cong Wang, Qian Wang, and Xiahua Jia
  IEEE Transactions on Dependable and Secure Computing (TDSC), 2024

• Privacy Enhanced Authentication for Online Learning Healthcare Systems
  Jianghua Liu, Jian Yang, Xingyi Huang, Lei Xu*, and Yang Xiang
  IEEE Transactions on Services Computing (TSC), 2024

• Practical Multi-Source Multi-Client Searchable Encryption With Forward Privacy: Refined Security Notion and New Constructions
  Lin Mei, Chungen Xu, Lei Xu, Xingliang Yuan, and Joseph K. Liu
  IEEE Transactions on Dependable and Secure Computing (TDSC), 2024

• Toward Quality-aware Data Valuation in Learning Algorithms: Practices, Challenges, and Beyond
  Lei Xu, Jiaqing Chen, Shan Chang, Cong Wang, and Bo Li
  IEEE Network Magazine, 2023

• Towards Efficient Cryptographic Data Validation Service in Edge Computing
  Lei Xu*, Xingliang Yuan, Zhengxiang Zhou, Cong Wang, and Chungen Xu
  IEEE Transactions on Services Computing (TSC), vol.16, no.1, pp. 656 - 669, 2023

• PEBA: Enhancing User Privacy and Coverage of Safe Browsing Services
  Yuefeng Du, Huayi Duan, Lei Xu, Helei Cui, Cong Wang, Qian Wang
  IEEE Transactions on Dependable and Secure Computing (TDSC), vol.20, no.5, pp.4343 - 4358, 2023

• Toward a Secure, Rich, and Fair Query Service for Light Clients on Public Blockchains
  Chengjun Cai, Lei Xu, Anxin Zhou, and Cong Wang
  IEEE Transactions on Dependable and Secure Computing (TDSC), vol.19, no.6, pp.3640 - 3655, 2022

• Forward and Backward Private DSSE for Range Queries
  Cong Zuo, Shifeng Sun, Joseph K. Liu, Jun Shao, Josef Pieprzyk, and Lei Xu
  IEEE Transactions on Dependable and Secure Computing (TDSC), vol.19, no.1, pp.328 - 338, 2022

• Interpreting and Mitigating Leakage-Abuse Attacks in Searchable Symmetric Encryption
  Lei Xu, Huayi Duan, Anxin Zhou, Xingliang Yuan, and Cong Wang
  IEEE Transactions on Information Forensics and Security (TIFS), vol.16, pp.5310 - 5325, 2021

• Enabling Authorized Encrypted Search for Multi-Authority Medical Databases
  Lei Xu, Shifeng Sun, Xingliang Yuan, Joseph Liu, Cong Zuo, and Chungen Xu
  IEEE Transactions on Emerging Topics in Computing (TETC), vol.9, no.1, pp.534 - 546, 2021

📖 Experiences and Educations

• 2020.09 - To Date, Associate Professor, Nanjing University of Science and Technology.
• 2023.02 - 2024.01, Research Associate, supervised by by Cong Wang, Department of Computer Science, City University of Hong Kong.
• 2019.04 - 2020.09, Postdoctoral, supervised by by Cong Wang, Department of Computer Science, City University of Hong Kong.
• 2017.04 - 2018.04, Joint training PhD student, supervised by Xingliang Yuan and Joseph Liu, Faculty of IT, Monash University.
• 2012.09 - 2019.09, PhD in Mathematics, supervised by Chungen Xu and Zhipeng Qiu, Nanjing University of Science and Technology.
• 2008.09 - 2012.06, Bachelor of Science in Mathematics and Applied Mathematics, Anhui Normal University.

💻 Services

Technical Program Committee Member

• 2025: ACM AsiaCCS
• 2024: IEEE MSN, PST, CIKM
• 2023: EAI TRIDENTCOM
• 2021: Qshine
• 2020: BlockApp

Reviewer and External Reviewer

• AsiaCrypt 2024, AsiaCrypt 2023, Trustcom 2020, etc.
• IEEE TDSC, IEEE TIFS, IEEE TSC, IEEE TKDE, IEEE IOTJ, etc.