About Me

I am currently a research fellow (EPSRC Fellow) in the Information Security Group at Royal Holloway, University of London. Previously, I was a post-doc in the same group, hosted by Pr Martin R. Albrecht. Before that, I did my PhD at IRIF, Université de Paris under the supervision of Frédéric Magniez. Prior to that, I studied at École polytechnique, at Télécom ParisTech and at Parisian Master of Research in Computer Science (MPRI).

Contact: yixin.shen at rhul.ac.uk

Curriculum Vitæ

You can download my CV here.

Research Interests

I mainly study quantum algorithms in the context of cryptanalysis. I am particularly interested in problems related to lattice-based cryptography. I am also interested in broader topics such as theoretical computer science or computational complexity.

Grant

I am the principal investigator of EP/W02778X/1 (08/2022-07/2027).

PhD Students

Ethan Davies (2022-) (co-advised with Alastair Kay)

Publications

1. Faster Dual Lattice Attacks by Using Coding Theory
   Kevin Carrier, Yixin Shen, Jean-Pierre Tillich
   Preprint 2022 [eprint]

2. Quantum Augmented Dual Attack
   Martin R. Albrecht, Yixin Shen
   Preprint 2022. Contributed talk at NIST 4th PQC Standardization Conference. [arXiv]

3. Finding many Collisions via Reusable Quantum Walks
   Xavier Bonnetain, André Chailloux, André Schrottenloher, Yixin Shen
   Preprint 2022. [arXiv]

4. Variational quantum solutions to the Shortest Vector Problem
   Martin R. Albrecht, Miloš Prokop, Yixin Shen, Petros Wallden
   Preprint 2022. [arXiv]

5. Improved Classical and Quantum Algorithms for the Shortest Vector Problem via Bounded Distance Decoding
   Divesh Aggarwal, Yanlin Chen, Rajendra Kumar, Yixin Shen
   Extended version of STACS 2021 with major differences. Contributed talk at the 25th Conference on Quantum Information Processing (QIP 2022). [arXiv]

6. Improved (Provable) Algorithms for the Shortest Vector Problem via Bounded Distance Decoding
   Divesh Aggarwal, Yanlin Chen, Rajendra Kumar, Yixin Shen
   38th International Symposium on Theoretical Aspects of Computer Science (STACS 2021) [PDF]

   Invited to TOCS Special Issue for STACS 2021 (regretfully declined).

7. Fast Classical and Quantum Algorithms for Online k-server Problem on Trees
   Ruslan Kapralov, Kamil Khadiev, Joshua Mokut, Yixin Shen, Maxim Yagafarov
   22th Italian Conference on Theoretical Computer Science (ICTCS 2021) [PDF] [arXiv]

8. Improved Classical and Quantum Algorithms for Subset-Sum
   Xavier Bonnetain, Rémi Bricout, André Schrottenloher, Yixin Shen
   26th International Conference on the Theory and Application of Cryptology and Information Security (ASIACRYPT 2020)
   [PDF] [arXiv]

9. Quantum Query Complexity of Dyck Languages with Bounded Height
   Kamil Khadiev, Yixin Shen
   Preprint 2019. [arXiv]

   Merged with Quantum Lower Bounds for 2D-Grid and Dyck Language
   Andris Ambainis, Kaspars Balodis, Jānis Iraids, Krišjānis Prūsis, Juris Smotrovs [arXiv]

   Merged version: Quantum Lower and Upper Bounds for 2D-Grid and Dyck Language
   45th International Symposium on Mathematical Foundations of Computer Science (MFCS 2020) [PDF]
   

10. Quantum lattice enumeration and tweaking discrete pruning
    Yoshinori Aono, Phong Nguyen, Yixin Shen
    24th International Conference on the Theory and Application of Cryptology and Information Security (ASIACRYPT 2018)
    [PDF] [eprint]

Scientific Talks

• Faster Dual Lattice Attacks by Using Coding Theory
  • GT Codes-Crypto Inria Paris, 2022
• Quantum Augmented Dual Attack
  • NIST 4th PQC Standardization Conference, 2022
  • Quantum Cryptanalysis Workshop, University of Bristol, 2022
• Finding many Collisions via Reusable Quantum Walks
  • Quantum Software Lab Workshop, University of Edinburgh, 2022
  • Bristol QIT Seminar, University of Bristol, 2022
  • IRIF Seminar, Université Paris Cité, 2022
• Improved Classical and Quantum Algorithms for the Shortest Vector Problem via Bounded Distance Decoding
  • GT info-quantique LaBRI, Univeresité de Bordeaux, 2022
  • Séminaire ECO LIRMM, Université de Montpellier, 2022
• Provable quantum algorithms for SVP
  • Dagstuhl Seminar 21421 Quantum Cryptanalysis, 2021
• Improved (Provable) Algorithms for the Shortest Vector Problem via Bounded Distance Decoding
  • ISG Seminar, Royal Holloway University of London, 2021
• Improved Classical and Quantum Algorithms for Subset-Sum
  • Joint Inria-IRIF Seminar, 2020
  • Chinese Academy of Sciences, 2020
  • Asiacrypt, 2020
  • Journées Codage & Cryptographie, 2020
• Quantum Lattice Enumeration and Treaking Discrete Pruning
  • European Quantum Technology Conference, 2019
  • Journées Informatique Quantique, 2019
  • Journées Codage & Cryptographie, 2018
  • Asiacrypt, 2018
• The shortest vector problem: Classical and Quantum Approaches
  • ATOS, France, 2019
  • CQIS seminar, University of Technology Sydney, 2018

Media Outreach

Panelist at the Responsible Quantum Summit organised by Tortoise Media:

"What are the implications of advancements in quantum technology for the security?"

Teaching Assistant

• Advanced Object-Oriented Programming, Licence 3, Fall 2019, Instructor: Aldric Degorre.
• Object-oriented Programming and User Interfaces, Licence 2, Fall 2017-2018, Instructor: Cristina Sirangelo.
• Introduction to Java Programming, Licence 1, Falls 2017-2018-2019, Instructors: Arnaud Sangnier.

Service

Program committee member: INDOCRYPT 2022.

Conference Reviewer: TQC 2019, ANTS 2020, SODA 2021, ICALP 2021, CRYPTO 2021, ASIACRYPT 2021, SAC 2021, TQC 2022, ASIACRYPT 2022, TCC 2022, SODA 2022, PKC 2022.

Journal Reviewer: ACM Transaction on Quantum Computing, Designs Codes and Cryptography.

Member of the EPSRC Peer Review College.

Seminar organizer: ENSL/CWI/RHUL Joint Online Cryptography seminars.

Workshop organizer: QUANTALGO Workshop 2018.