Shuichi Katsumata

*Please call me "Shu" for short. Pronounced exactly like "shoe".

Intro.

I'm a cryptography researcher at National Institute of Advanced Industrial Science and Technology (AIST), Japan. I'm also affiliated with PQShield as a research consultant.

My main research topics include, but not limited to, lattices-based crypto, identity-based encryptions, group/attribute-based signatures, zero-knowledge proofs, and so on.

I'm always thrilled, excited, and motivated to discuss any interesting problems with other researchers so please let me know if you are interested!!

Contact: shuichi.katsumata000 [at] gmail.com OR shuichi.katsumata [at] aist.go.jp

Publications

International Conference

2020

ASIACRYPT 2020. To Appear.

ASIACRYPT 2020. ePrint.

ASIACRYPT 2020. ePrint.

CRYPTO 2020. ePrint.

*(Historical Note: This is a major updated version of eprint:DKNYY18 with many new results, which itself is a merged version of eprint:DavNis18 and eprint:KatYam18.)

    • Exposing Private User Behaviors of Collaborative Filtering via Model Inversion Techniques. Seira Hidano, Takao Murakami, Shuichi Katsumata, Shinsaku Kiyomoto, Goichiro Hanaoka.

PETS/PoPETS 2020. To Appear.

    • Non-Interactive Zero-Knowledge in Pairing-Free Groups from Weaker Assumptions. Geoffroy Couteau, Shuichi Katsumata, Bogdan Ursu.

EUROCRYPT 2020. ePrint. video (by Bogdan Ursu).

EUROCRYPT 2020. ePrint. video.

PKC 2020. ePrint.

2019

CRYPTO 2019. ePrint. video.

    • Identity-Based Encryption with Security against the KGC: A Formal Model and Its Instantiation from Lattices. Keita Emura, Shuichi Katsumata, Yohei Watanabe.

ESORICS 2019. ePrint.

    • Group Signatures without NIZK: From Lattices in the Standard Model. Shuichi Katsumata, Shota Yamada.

EUROCRYPT 2019. ePrint.

EUROCRYPT 2019. ePrint. video.

    • Non-Zero Inner Product Encryption Schemes from Various Assumptions: LWE, DDH and DCR. Shuichi Katsumata, Shota Yamada.

PKC 2019. ePrint.

PKC 2019. ePrint.

2018

ASIACRYPT 2018. (Invited to Journal of Cryptography.) ePrint.

    • Attribute-Based Signatures for Unbounded Languages from Standard Assumptions. Yusuke Sakai, Shuichi Katsumata, Nuttapong Attrapadung, Goichiro Hanaoka.

ASIACRYPT 2018. ePrint.

    • Attribute-Based Signatures for Unbounded Circuits in the ROM and Efficient Instantiations from Lattices. Ali El Kaafarani, Shuichi Katsumata.

PKC 2018. ePrint.

    • Anonymous Reputation Systems Achieving Full Dynamicity from Lattices. Ali El Kaafarani, Shuichi Katsumata, Ravital Solomon.

FC 2018. Preproceeding.

2017

    • On the Untapped Potential of Encoding Predicates by Arithmetic Circuits and Their Applications. Shuichi Katsumata.

ASIACRYPT 2017. ePrint. video.

    • Model Inversion Attacks for Prediction Systems: Without Knowledge of Non-Sensitive Attributes. Seira Hidano, Takao Murakami, Shuichi Katsumata, Shinsaku Kiyomoto, Goichiro Hanaoka.

PST 2017. Proceeding.

2016

    • Partitioning via Non-linear Polynomial Functions: More Compact IBEs from Ideal Lattices and Bilinear Maps. Shuichi Katsumata, Shota Yamada.

ASIACRYPT 2016. ePrint. video.

2015

    • Robust Cost Sensitive Support Vector Machine. Shuichi Katsumata, Akiko Takeda.

AISTATS 2015. Proceedings.

2014

    • Constructing Subspace Membership Encryption through Inner Product Encryption. Shuichi Katsumata, Noboru Kunihiro.

ProvSec 2014. Proceedings.


Journal Articles

2020

Theoretical Computer Science, Volume 809, 2020. Elsevier. (Full version of [KMT19@PKC]).

2018

    • Model Inversion Attacks for Prediction Systems: Without Knowledge of Non-Sensitive Attributes. Seira Hidano, Takao Murakami, Shuichi Katsumata, Shinsaku Kiyomoto, Goichiro Hanaoka.

IEICE Transactions E101-D(11), 2018. (Full version of [HMKKH18@PST]).

2017

    • Constructing Subspace Membership Encryption through Inner Product Encryption. Shuichi Katsumata, Noboru Kunihiro.

IEICE Transactions E100-A(9), 2017. (Full version of [KK14@ProvSec]).

Talks


    • Exploring Constructions of Compact NIZKs from Various Assumptions.

Workshop on Cryptography and Information Security (WCIS), September, 2019. (slides).

    • Exploring Links Between Lattice-based NIZKs and Various Signature Schemes (in the Standard Model).

The Workshop on Modern Trends in Cryptography, June, 2019. (slides).

    • On the Untapped Potential of Encoding Predicates by Arithmetic Circuits and Their Applications.

NTT-JFLI-U.Tokyo Workshop on Cryptography, January, 2018.

Tokyo Crypto Day, March, 2018. (slides).

ISEC, May, 2018.

    • Partitioning via Non-linear Polynomial Functions: More Compact IBEs from Ideal Lattices and Bilinear Maps.

10th Workshop on Public Key Cryptography: Secure Constructions and Its Applications, February, 2017.

ISEC, May, 2017. (slides).

    • Lattice IBE without Reduction Loss in the Random Oracle Model.

SCIS/CSS Invited Session in IWSEC, September, 2016.

Activities

Program Committee

    • ProvSec 2020.

Subreviewer

    • CRYPTO, EUROCRYPT, ASIACRYPT, TCC, PKC, ACNS, PQCrypto, ACISP, APKC, IWSEC, DCC, etc...

Organizer

Affiliation

Awards

  • Director's Award, Graduate School of Frontier Sciences, The University of Tokyo. May, 2019.

  • Invited to Journal of Cryptography from ASIACRYPT 2018.

  • Tsujii Shigeo Security Award, 2018.

  • Computer Security Symposium 2017 (CSS2017), Best Student Paper Award.

  • Research Fellowships for Doctoral Scientists, Japan Society for the Promotion of Science (JSPS). 2017.

  • Tsujii Shigeo Security Award, 2017.

  • Symposium on Cryptography and Information Security 2016 (SCIS 2016), Best Paper Award.