NSF CAREER: Exact Optimal and Data-Adaptive Algorithms and Tools for Differential Privacy


Principal Investigator
Yu-Xiang Wang, UCSB (2021 - 2024), UCSD (2024 -)
 
Project Summary
Talks  |  Products  |  Education

Funded by NSF CNS 2048091.

This material is based upon work supported by the National Science Foundation under Grant No. 2048091. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.

Project Summary

Differential privacy (DP) is a rigorous way to learn from sensitive data while limiting what can be inferred about any one person. This CAREER project developed mathematical foundations, algorithms, software, and educational resources that make DP more accurate, adaptable, and practical. The research produced exact tools for tracking privacy risk across complex analyses; data-adaptive and per-person privacy methods; and private learning techniques for classification, data valuation, reinforcement learning, online decision-making, and language models. The project also expanded the open-source AutoDP library so that researchers and practitioners can use state-of-the-art privacy accounting more reliably.

The award supported doctoral students, a postdoctoral researcher, and undergraduate researchers, and its results were incorporated into graduate teaching and hands-on student projects. Recent work extends the project to the responsible use of artificial intelligence: Private-RAG protects document collections while answering many questions; DPCheatSheet teaches people to recognize common privacy-programming errors; and DPrivBench tests whether large language models can reason correctly about formal privacy guarantees. Papers, code, tutorials, and presentation materials are publicly available below.

Map of equivalent differential privacy representations

Fig. 1. Exact optimal DP accounting represents a privacy mechanism by a function and converts losslessly among commonly used privacy descriptions.

2024 NSF SaTC project poster

Fig. 2. Project overview presented at the 2024 NSF Secure and Trustworthy Cyberspace Principal Investigator Meeting. Click the poster to view the PDF.

Talks and media coverage

  1. Oral presentation on "DPrivBench: Benchmarking LLMs' Reasoning for Differential Privacy"
    Erchi Wang presented at the Theory and Practice of Differential Privacy (TPDP) 2026 workshop.
  2. Oral presentations on "Adapting to Linear Separable Subsets with Large-Margin in Differentially Private Learning" and "Purifying Approximate Differential Privacy with Randomized Post-processing"
    Erchi Wang and Yingyu Lin presented at the Theory and Practice of Differential Privacy (TPDP) 2025 workshop.
  3. Invited presentation on recent advances in differential privacy
    PI Wang presented at a differential privacy workshop in Bertinoro, Italy, in 2025.
  4. Conference presentations of private learning and privacy-purification results
    PI Wang and coauthors presented project-supported work at ICML 2025 and NeurIPS 2025; "Purifying Approximate Differential Privacy with Randomized Post-processing" received a NeurIPS Spotlight.
  5. Project poster at the 2024 NSF SaTC Principal Investigator Meeting
    PI Wang presented the project's research, software, and educational outcomes in Pittsburgh, Pennsylvania. [Poster PDF]
  6. Presentations and AutoDP dissemination at TPDP 2024
    PI Wang and coauthors presented project-supported research and shared AutoDP with the community in Boston.
  7. Paper "Neural Collapse Meets Differential Privacy" is selected for an Oral Presentation at ICML 2024
    Among the top 0.3% of all submissions.
  8. Invited talk on "Open Problem: Near Linear time algorithm for DP-ERM"
    PI Wang spoke at TTIC Federated Learning Workshop, 2023
  9. Invited talk on "How to Squeeze out the Last Drop of Utility in your DP application"
    PI Wang spoke at TTIC Federated Learning Workshop, 2023
  10. Invited talk on "Towards Practical Differential Privacy"
    PI Wang spoke at Nokia Bell Lab, UCSD, Princeton in 2023
  11. Keynote talk on "Practical Differential Privacy"
    PI Wang spoke at NeurIPS'22 Workshop on "Challenges in Deploying and Monitoring Machine Learning Systems"
  12. Invited talk on "Towards Practical Differential Privacy with Differential Privacy-like ideas"
    PI Wang spoke at Google Research Workshop on "Security, Privacy, and Anti-Abuse Research Workshop"
  13. Invited talk on "Optimal Accounting of Differential Privacy"
    PI Wang spoke at MIT Media Lab and LinkedIn Data Science Seminar Series
  14. Invited talk on "Optimal Accounting of Differential Privacy via Characteristic Function"
    PI Wang spoke at Rutgers. Jinshuo and Yuqing spoke at Google.
  15. Invited talk on "Per-instance Differential Privacy and How to Privately Publish Them"
    PI Wang spoke at Google and at University of Albany
  16. Invited talk on "Advances in Differential Privacy and Private Federated Learning"
    PI Wang spoke at Amazon Web Services.
  17. News article "A Matter of Privacy"
    Coverage on this project on UCSB Magazine "The Current" [Link]
  18. Invited talk on "Privacy Amplification by Sampling and Renyi Differential Privacy"
    PI Wang spoke at Berkeley Simons Institute [Link to the talk]

Research Results

  1. DPrivBench: Benchmarking LLMs' Reasoning for Differential Privacy
    Erchi Wang, Pengrun Huang, Eli Chien, Om Thakkar, Kamalika Chaudhuri, Yu-Xiang Wang, Ruihan Wu.
    Manuscript. [arxiv]
  2. Private-RAG: Answering Multiple Queries with LLMs while Keeping Your Data Private
    Ruihan Wu, Erchi Wang, Zhiyuan Zhang, Yu-Xiang Wang.
    COLM 2026. [arxiv]
  3. Improved Regret in Stochastic Decision-Theoretic Online Learning under Differential Privacy
    Ruihan Wu, Yu-Xiang Wang.
    ALT 2026. [arxiv]
  4. Purifying Approximate Differential Privacy with Randomized Post-processing
    Yingyu Lin, Erchi Wang, Yi-An Ma, Yu-Xiang Wang.
    NeurIPS 2025. (*Spotlight Presentation) [arxiv]
  5. DPCheatSheet: Using Worked and Erroneous LLM-usage Examples to Scaffold Differential Privacy Implementation
    Shao-Yu Chu, Yuhe Tian, Yu-Xiang Wang, Haojian Jin.
    Manuscript under submission. [arxiv]
  6. Adapting to Linear Separable Subsets with Large-Margin in Differentially Private Learning
    Erchi Wang, Yuqing Zhu, Yu-Xiang Wang.
    ICML 2025. [arxiv]
  7. Differentially Private Reinforcement Learning with Self-Play
    Dan Qiao, Yu-Xiang Wang.
    NeurIPS 2024. [arxiv]
  8. Differentially Private Bias-Term only Fine-tuning of Foundation Models
    Zhiqi Bu, Yu-Xiang Wang, Sheng Zha, George Karypis.
    ICML 2024. [arxiv]
  9. Neural Collapse meets Differential Privacy: Curious behaviors of NoisyGD with Near-Perfect Representation Learning
    Chendi Wang, Yuqing Zhu, Weijie Su, Yu-Xiang Wang
    ICML 2024. [arxiv] (*Oral Presentation)
  10. Privacy Profiles for Private Selection
    Antti Koskela, Rachel Redberg, Yu-Xiang Wang.
    ICML 2024. [arxiv]
  11. Tractable MCMC for Private Learning with Pure and Gaussian Differential Privacy
    Yingyu Lin, Yi-An Ma, Yu-Xiang Wang, Rachel Redberg.
    ICLR 2024. [arxiv]
  12. Advancing Differential Privacy: Where We Are Now and Future Directions for Real-World Deployment
    Participants of 2022 June Workshop "Differential Privacy: Challenges Towards The Next Fronter".
    Harvard Data Science Review [paper, arxiv]
  13. Improving the Privacy and Practicality of Objective Perturbation for Differentially Private Linear Learners
    Rachel Redberg, Antti Koskela, Yu-Xiang Wang.
    NeurIPS 2023. [arxiv]
  14. Threshold KNN-Shapley: A Linear-Time and Privacy-Friendly Approach to Data Valuation
    Jiachen T. Wang, Yuqing Zhu, Yu-Xiang Wang, Ruoxi Jia, Prateek Mittal.
    NeurIPS 2023. [arxiv] (*Spotlight Presentation)
  15. Offline Reinforcement Learning with Differential Privacy
    Dan Qiao, Yu-Xiang Wang.
    NeurIPS 2023. [arxiv]
  16. "Private Prediction Strikes back!" Private Kernelized Nearest Neighbors with Individual Renyi Filter
    Yuqing Zhu, Xuandong Zhao, Chuan Guo, Yu-Xiang Wang.
    UAI 2023. [arxiv] (*Spotlight Presentation)
  17. Near-Optimal Differentially Private Reinforcement Learning
    Dan Qiao, Yu-Xiang Wang.
    AISTATS 2023 [arxiv]
  18. Generalized PTR: User-Friendly Recipes for Data-Adaptive Algorithms with Differential Privacy
    Rachel Redberg, Yuqing Zhu, Yu-Xiang Wang.
    AISTATS 2023. [arxiv] (*Plenary Oral Presentation)
  19. Differentially Private Linear Sketches: Efficient Implementations and Applications
    Fuheng Zhao, Dan Qiao, Rachel Redberg, Divyakant Agrawal, Amr El Abbadi, Yu-Xiang Wang.
    NeurIPS 2022. [arxiv]
  20. SeqPATE: Differentially Private Text Generation via Knowledge Distillation
    Zhiliang Tian, Yingxiu Zhao, Ziyue Huang, Yu-Xiang Wang, Nevin Zhang, He He
    NeurIPS 2022. [openreview]
  21. Provably Confidential Language Modelling
    Xuandong Zhao, Lei Li, Yu-Xiang Wang.
    NAACL 2022. [arxiv] (*Oral Presentation)
  22. Adaptive Private-K-Selection with Adaptive K and Application to Multi-label PATE
    Yuqing Zhu, Yu-Xiang Wang.
    AISTATS 2022. [arxiv]
  23. Optimal Accounting of Differential Privacy via Characteristic Function
    Yuqing Zhu, Jinshuo Dong, Yu-Xiang Wang.
    AISTATS 2022. [arxiv]
  24. Privately Publishable Per-instance Privacy
    Rachel Redberg, Yu-Xiang Wang.
    NeurIPS 2021. [arxiv]
  25. Revisiting Model-Agnostic Private Learning: Faster Rates and Active Learning
    Chong Liu, Yuqing Zhu, Kamalika Chaudhuri, Yu-Xiang Wang
    Journal of Machine Learning Research. Shorter version appeared in AISTATS 2021. [arxiv]
  26. Voting-based Approaches For Differentially Private Federated Learning
    Yuqing Zhu, Xiang Yu, Yi-Hsuan Tsai, Francesco Pittaluga, Masoud Faraki, Manmohan chandraker and Yu-Xiang Wang
    Manuscript. [arxiv]
  27. Subsampled Renyi Differential Privacy and Analytical Moments Accountant
    Yu-Xiang Wang, Borja Balle, Shiva Kasiviswanathan
    Journal of Privacy and Confidentiality, 2021 [ paper ]. A shorter version appeared at AISTATS 2019 and received a Notable Paper Award.

Educational materials

  1. DSC 291: Differential Privacy—Theory, Algorithms and Applications [Course website]
    Instructor: Yu-Xiang Wang, UC San Diego, Fall 2024.
  2. Privacy in Practice: hands-on privacy telemetry projects [Project website]
    Undergraduate capstone projects connecting formal privacy guarantees with practical data collection and machine-learning applications.
  3. CS291A Introduction to Differential Privacy: Theory, Algorithms and Applications [Course website]
    Instructor: Yu-Xiang Wang, 2021 Fall
  4. [Open source project] New API / examples / tutorials / unit tests for autodp
    Contributors: Yu-Xiang Wang, Yuqing Zhu, Borja Balle (DeepMind), Stefan Mallem (Google)
  5. Guest Lecture on "Composition, RDP and Amplification by Sampling"
    at Mijung Park's CPSC 532P at University of British Columbia [Course website]

Fig. 3. The AutoDP application programming interface for composing and calibrating differentially private mechanisms.