Yongjun Zhao

I am a Research Scientist at TikTok in the Privacy Innovation Lab, working on privacy-enhancing technologies (PETs) and their deployment in real-world systems. Prior to joining TikTok, I was a Senior Research Fellow at the Strategic Centre for Research in Privacy-Preserving Technologies & Systems (SCRIPTS), Nanyang Technological University (NTU), and a Research Fellow at NTU. I received my Ph.D. in Information Engineering from The Chinese University of Hong Kong in 2018, advised by Prof. Sherman S. M. Chow. I also hold a B.Eng. in Information Engineering (First Class Honors) from CUHK.

My research focuses on applied cryptography and PETs, including private set operations, privacy-preserving machine learning, searchable encryption and cryptographic proofs for cloud storage, digital signatures and anonymous credentials, and privacy-preserving payment/blockchain systems. I have served on program committees for venues such as AAAI, PoPETs, ICDCS, and PPAI, and as an external reviewer for CRYPTO, CCS, IEEE TDSC/TIFS, and many others.

news

Jan 15, 2026 Our paper “Secure Join Operations in Multi-Identifier Databases: Performance and Practicality” has been accepted to VLDB 2026.
Jul 10, 2025 Gave a lightning talk, “Making PETs Work for You,” at the PETs Summit in Singapore.
Jan 20, 2025 Two papers accepted: “Privacy-Preserving Screening for Record Linkage” at ICDE 2025 and “Batch Anonymous MAC Tokens from Lattices” at PQCrypto 2025.
Jul 15, 2024 Presented “Synergizing DP and MPC for Privacy-Preserving Ad Measurement” at the Privacy-Enhancing Technology Summit Asia-Pacific 2024 in Singapore.
Dec 01, 2022 Joined TikTok as a Research Scientist in the Privacy Innovation Lab, working on privacy-enhancing technologies.

selected publications

  1. VLDB’26
    Secure Join Operations in Multi-Identifier Databases: Performance and Practicality
    Wenjie Lu , Yongchuan Niu , Yongjun Zhao, Wei Dai , Donghang Lu , and Qiang Yan
    In Proceedings of the 52nd International Conference on Very Large Data Bases, VLDB 2026 , 2026
    to appear
  2. ICDE’25
    Privacy-Preserving Screening for Record Linkage
    Chenyu Huang , Fan Zhang , Huangxun Chen , Yongjun Zhao, Huaming Rao , Peng Chen , and Danqing Huang
    In 41st IEEE International Conference on Data Engineering, ICDE 2025, Hong Kong, May 19–23, 2025 , 2025
    PDF
  3. PQCrypto’25
    Batch Anonymous MAC Tokens from Lattices
    Yingfei Yan , Sherman S. M. Chow , Lucien K. L. Ng , Harry W. H. Wong , Yongjun Zhao, and Baocang Wang
    In Post-Quantum Cryptography - 16th International Workshop, PQCrypto 2025, Taipei, Taiwan, April 8–10, 2025, Proceedings, Part I , 2025
  4. CT-RSA’24
    Lattice-based Threshold, Accountable, and Private Signature
    Yingfei Yan , Yongjun Zhao, Wen Gao , and Baocang Wang
    In Topics in Cryptology - CT-RSA 2024 - Cryptographers’ Track at the RSA Conference 2024, San Francisco, CA, USA, May 6–9, 2024, Proceedings , 2024
  5. IEEE TIFS
    Enabling Threshold Functionality for Private Set Intersection Protocols in Cloud Computing
    Jingwei Hu , Yongjun Zhao, Benjamin Hong Meng Tan , Khin Mi Mi Aung , and Huaxiong Wang
    IEEE Trans. Inf. Forensics Secur., 2024
  6. NDSS’21
    Let’s Stride Blindfolded in a Forest: Sublinear Multi-Client Decision Trees Evaluation
    Jack P. K. Ma , Raymond K. H. Tai , Yongjun Zhao, and Sherman S. M. Chow
    In 28th Annual Network and Distributed System Security Symposium, NDSS 2021 , 2021
    PDF
  7. IEEE TDSC
    Updatable Block-Level Message-Locked Encryption
    Yongjun Zhao, and Sherman S. M. Chow
    IEEE Trans. Dependable Secur. Comput., 2021
  8. PKC’19
    Let a Non-Barking Watchdog Bite: Cliptographic Signatures with an Offline Watchdog
    Sherman S. M. Chow , Alexander Russell , Qiang Tang , Moti Yung , Yongjun Zhao, and Hong-Sheng Zhou
    In Public-Key Cryptography - PKC 2019 - 22nd IACR International Conference on Practice and Theory of Public-Key Cryptography, Beijing, China, April 14–17, 2019, Proceedings, Part I , 2019