Luowen Qian

Email: l.<lastname>@northeastern.edu or <firstname>@qcry.pt

I am currently a postdoc at the CIS Lab at NTT Research, Inc. supervised by Mark Zhandry. Prior to that, I was a graduating Ph.D. student at Boston University advised by Ran Canetti. My research interest is mainly on quantum computation and cryptography.

I will be joining Northeastern in 2026! Please apply to Khoury College of Computer Sciences if you are interested in working with me.

Publications

1. Unitary Complexity and the Uhlmann Transformation Problem
   John Bostanci, Yuval Efron, Tony Metger, Alexander Poremba, Luowen Qian, Henry Yuen
   ITCS 2026 [arXiv] (contributed long plenary talk at QIP 2024)
2. Quantum-Computable One-Way Functions without One-Way Functions
   William Kretschmer, Luowen Qian, Avishay Tal
   STOC 2025 [arXiv] (contributed talk at QIP 2025)
3. Hard Quantum Extrapolations in Quantum Cryptography
   Luowen Qian, Justin Raizes, Mark Zhandry
   EUROCRYPT 2025 [arXiv]
4. Unconditionally secure quantum commitments with preprocessing
   Luowen Qian
   CRYPTO 2024 [arXiv] (contributed talk at QIP 2025)
5. An efficient quantum parallel repetition theorem and applications
   John Bostanci, Luowen Qian, Nicholas Spooner, Henry Yuen
   STOC 2024 [arXiv] (contributed short plenary talk at QIP 2024)
6. Quantum Cryptography in Algorithmica
   William Kretschmer, Luowen Qian, Makrand Sinha, Avishay Tal
   STOC 2023 [arXiv] (contributed talk at QIP 2023, invited talk at QCrypt 2023)
7. On the computational hardness needed for quantum cryptography
   Zvika Brakerski, Ran Canetti, Luowen Qian
   ITCS 2023 [ePrint]
8. Collusion-Resistant Functional Encryption for RAMs
   Prabhanjan Ananth, Kai-Min Chung, Xiong Fan, Luowen Qian
   ASIACRYPT 2022 [ePrint]
9. Collusion Resistant Copy-Protection for Watermarkable Functionalities
   Jiahui Liu, Qipeng Liu, Luowen Qian, Mark Zhandry
   TCC 2022 [ePrint] (contributed talk at QIP 2023)
10. Pseudorandom (Function-Like) Quantum State Generators: New Definitions and Applications
    Prabhanjan Ananth, Aditya Gulati, Luowen Qian, Henry Yuen
    TCC 2022 [arXiv] (contributed talk at QCrypt 2022, short plenary talk merged with AQY22 at QIP 2023)
11. Cryptography from Pseudorandom Quantum States
    Prabhanjan Ananth, Luowen Qian, Henry Yuen
    CRYPTO 2022 [ePrint] (contributed short plenary talk merged with AGQY22 at QIP 2023)
12. Beating Classical Impossibility of Position Verification
    Jiahui Liu, Qipeng Liu, Luowen Qian
    ITCS 2022 [arXiv]
13. Tight Quantum Time-Space Tradeoffs for Function Inversion
    Kai-Min Chung, Siyao Guo, Qipeng Liu, Luowen Qian
    FOCS 2020 [arXiv] (invited keynote at TQC 2021)
14. Lower Bounds for Function Inversion with Quantum Advice
    Kai-Min Chung, Tai-Ning Liao, Luowen Qian
    ITC 2020 [arXiv]
15. Adaptively Secure Garbling Schemes for Parallel Computations
    Kai-Min Chung, Luowen Qian
    TCC 2019 [ePrint]

Selected talks

1. Impersonating Quantum Secrets over Classical Channels
   YITP Workshop Kyoto Quantum Crypto 2 (October 22, 2025)
2. Cryptographic Applications of Quantum Computational Advantages
   Stanford QIQC Seminar (May 6, 2025)
3. Quantum-Computable One-Way Functions without One-Way Functions
   QIP 2025 (February 24, 2025) [Slides]
4. “One-Way Functions” without One-Way Functions
   Bay Area Crypto Day (November 1, 2024) [Slides]
5. Unconditionally secure commitments with quantum auxiliary inputs/preprocessing
   QIP 2025 (joint talk with Barak Nehoran; February 27, 2025); CRYPTO 2024 (joint talk with Barak Nehoran; August 20, 2024)
6. Unconditionally secure quantum commitments with preprocessing
   MIT Cryptography and Information Security seminar (February 16, 2024) [Slides]
7. An efficient quantum parallel repetition theorem and applications
   STOC 2024 (June 27, 2024); UCSD Theory Seminar (January 29, 2024) [Slides]
8. Quantum Cryptography in Algorithmica
   STOC 2023 (June 23, 2023); A special crypto day in honor of Ran Canetti on the occasion of his 60th birthday (May 12, 2023)
9. Quantum pseudorandomness in Algorithmica, and its implications to cryptography and complexity
   Minimal Complexity Assumptions for Cryptography workshop @ Simons Institute (May 5, 2023)
10. Cryptography from Quantum Pseudorandomness
    IQC Math and Computer Science Seminar (March 9, 2023) [Slides]
11. On the computational hardness needed for quantum cryptography
    ITCS 2023 (January 12, 2023); QCW 2022; Third Kyoto Workshop on Quantum Information, Computation, and Foundations (October 18, 2022) [Slides]; MIT Cryptography and Information Security seminar (September 30, 2022)
12. Cryptography from Pseudorandom Quantum States
    QCrypt 2022 contributed talk (August 29, 2022) [Video, Slides]; CRYPTO 2022 (August 15, 2022) [Video abstract, Slides, Recording]; UC Berkeley Theory CS Seminar (January 11, 2022) [Slides]
13. Beating Classical Impossibility of Position Verification
    QCW 2022; QIP 2022 contributed talk (March 10, 2022) [Recording]; Ottawa QUASAR seminar (March 4, 2022); ITCS 2022 (February 2, 2022) [Video, Recording]; Charles River Crypto Day (November 19, 2021); BUsec Seminar (September 29, 2021) [Slides]

Teaching

• Guest lecture for MIT 6.S895 (Spring 2024): Commitments from PRS, and oracle PRSs from weak assumptions
• Three guest lectures for GRS PY 896 (Spring 2023): Special Topics Seminar in Theoretical Physics. Quantum cryptography: from encryption to black hole paradoxes
• CAS CS 538: Fundamentals of Cryptography (Spring 2023), Teaching Fellow
  • Two lectures on pseudorandom generators
• CAS CS 538: Fundamentals of Cryptography (Spring 2022), Teaching Fellow
  • Guest lecture on quantum & cryptography
• CAS CS 332: Theory of Computation (Fall 2020), Teaching Fellow

Manuscripts

1. Impersonating Quantum Secrets over Classical Channels
   Luowen Qian, Mark Zhandry
   [arXiv]
2. Nonuniform Linear Depth Circuits Decide Everything
   Luowen Qian
   For April Fool's day, 2020 [viXra]