# Personal Information

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

Room 343,Engineering Building 6, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656

Tel: 03-5841-6940 (ext. 26940)

Fax:

E-mail：takagi@mist.i.u-tokyo.ac.jp

## Biography

March 1995 | M.Sc., Graduate School of Mathematics, Nagoya University, Japan |
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April 1995 | Researcher, NTT Laboratories, Tokyo |

October 1997 | Guest researcher, Department of Computer Science, Technische Universitaet Darmstadt, Germany |

October 1998 | Researcher, NTT Laboratories, Germany |

January 2001 | PhD with honors, Department of Computer Science, Technische Universitaet Darmstadt, Germany |

July 2002 | Assistant Professor, Department of Computer Science, Technische Universitaet Darmstadt, Germany |

April 2005 | Associate Professor, School of Systems Information Science, Future University Hakodate, Japan |

April 2008 | Professor, School of Systems Information Science, Future University Hakodate, Japan |

April 2010 | Professor, Faculty of Mathematics, Kyushu University, Japan |

April 2011 | Professor, Institute of Mathematics for Industry, Kyushu University, Japan |

April 2017 | Professor, Graduate School of Information Science and Technology, The University of Tokyo, Japan |

## Research Themes

We investigate the theory and practice of cryptography which underpins the security of our information society.

● Cryptography

We study post-quantum cryptography based on the mathematical problems (such as coding theory, lattice theory, multivariate polynomials, graph theory, etc), which are computationally intractable even in the era of quantum computing.

● Information Security

We are engaged in the development of new efficient cryptographic algorithms and implementation secure against physical attacks, which can be used in our life, for example, copyright protection, electronic voting, cryptocurrency, and so on.

## Main paper and books

- Tsuyoshi Takagi (Ed), “Post-Quantum Cryptography – 7th International Workshop, PQCrypto 2016,” LNCS 9606, Springer 2016.
- Kaoru Kurosawa, Tsuyoshi Takagi, “One-Wayness Equivalent to General Factoring,” IEEE Transactions on Information Theory, Vol.55, No.9, pp.4249-4262, 2009.
- Tsuyoshi Takagi, “A Fast RSA-Type Public-Key Primitive Modulo pkq,” IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol.E87-A, No.1, pp.94-100, 2004.