# Personal Information

**Department of Mathematical Informatics, Graduate School of Information Science and TechnologyLecturer**

Room 354,Engineering Building 6, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656

Tel: 03-5841-6959 (ext. 26959)

Fax:

E-mail：takayasu-a@g.ecc.u-tokyo.ac.jp

## Biography

March 2012 | Bachelor of Engineering, Department of Mathematical Engineering and Information Physics, Faculty of Engineering, The University of Tokyo |
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March 2014 | Master of Science, Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo |

March 2017 | Ph.D., Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo |

April 2017 | Research Associate, Department of Mathematical Informatics, Graduate School of Information Science and Technology, The University of Tokyo |

April 2020 | Senior Researcher, Security Fundamental Laboratory, Cybersecurity Research Institute, National Institute of Information and Communications Technology |

October 2021 | Lecturer, Department of Mathematical Informatics, Graduate School of Information Science and Technology, The University of Tokyo |

## Research Themes

We are conducting research on cryptography, which is a fundamental technology for the secure operation of the information society.

● Research on public-key cryptography, in particular, the construction and security proofs of post-quantum cryptosystems.

● Research on attack and solution algorithms for mathematical problems related to public key cryptosystems and their security.

## Main paper and books

- Atsushi Takayasu, Yao Lu, and Liqiang Peng. Small CRT-exponent RSA Revisited. Journal of Cryptology, Vol. 32, Issue 4, pp. 1337-1382, 2019.
- Shuichi Katsumata, Takahiro Matsuda, and Atsushi Takayasu. Lattice-based Revocable (Hierarchical) IBE with Decryption Key Exposure Resistance. Proc. PKC 2019, LNCS 11443, pp. 441-471, Springer, 2019.
- Atsushi Takayasu and Noboru Kunihiro. Partial Key Exposure Attacks on RSA: Achieving the Boneh-Durfee Bound. Theoretical Computer Science, Vol. 761, pp. 51-77, 2019.