Ryo FUJITA

本日の発表資料

Ryo FUJITA

Associate Professor, Research and Development Initiative, Chuo University

Research Interests

post quantum cryptography, multivariate cryptography,
fully homomorphic encryption, information security

Education

Ph. D. in Informatics
from Institute of Information Security (2009).
Advisor: Professor Shigeo Tsujii

Master of Engineering in Management Science
from Tokyo University of Science (2006).
Advisor: Professor Toshihiro Furukawa

Bachelor of Engineering in Management Science
from Tokyo University of Science (2004).
Advisor: Professor Noriaki Kano and Associate Professor Masaya Fujisawa

Publications and Presentations

  • Ryo Fujita:
    A study on risk of compromising of encryption in IT controls,
    Japan Society of Security Management (JSSM) 32nd national convention,
    June 16, 2018, College of Commerce, Nihon University, Tokyo, Japan. (In Japanese)

  • Ryo Fujita:
    Toward Promotion of Efforts for Automotive Cybersecurity Management,
    Japan Society of Security Management (JSSM) 31st national convention,
    July 30, 2017, Yokohama f college, Yokohama, Japan. (In Japanese)

  • Ryo Fujita, Yoshiki Sameshima, Yoshihiro Sawada, Sumio Hashimoto, and Hajime Kawaguchi:
    Vehicle Information Security in the information age of the whole world,
    Japan Society of Security Management (JSSM) 30th national convention,
    June 26, 2016, Kogakuin University, Shinjuku Campus, Tokyo, Japan. (In Japanese)

  • Ryo Fujita:
    Towards the realization of IT controls in Car Security,
    Japan Society of Security Management (JSSM) 29th national convention,
    June 27, 2015, Institute of Industrial Science, the University of Tokyo, Tokyo, Japan. (In Japanese)

  • Ryo Fujita:
    Toward secure utilization of personal data,
    Japan Society of Security Management (JSSM) 28th national convention,
    June 21, 2014, Tokyo University of Technology, Tokyo, Japan. (In Japanese)
    [slide (in Japanese)]

  • Ryo Fujita:
    Representation for nonlinear transformation of vector space over finite fields based on combinatorics,
    COmbinatorics Summer school 2013 (COS 2013), open problem session 1,
    September 2-5, 2013, Iwate, Japan. (In Japanese)

  • Ryo Fujita:
    On the practical application of cryptography,
    Japan Society of Security Management (JSSM) 27th national convention,
    June 22, 2013, Tokyo Denki University, Tokyo, Japan. (In Japanese)
    [slide (in Japanese)]

  • Shigeo Tsujii, Hiroshi Doi, Ryo Fujita, Masahito Gotaishi, Yukiyasu Tsunoo, and Takahiko Syouji:
    Privacy preserving data processing with collaboration of homomorphic cryptosystems,
    Revised Selected Papers from 16th International Conference on Financial Cryptography and Data Security (FC 2013) Workshops,
    USEC and WAHC 2013, Lecture Notes in Computer Science, Springer-Verlag, Vol.7862, pp.201-212, April 1, 2013, Okinawa, Japan.
    https://doi.org/10.1007/978-3-642-41320-9_14

  • Ryo Fujita:
    Piece in hand concept for enhancing security of multivariate public key cryptosystems and its applications,
    Forefront Workshop for the Promotion of the Academia-Industry Cooperation
    "Application of Computational Number Theory to Secure Social Infrastructure (II)
    - Solving Multivariate Polynomial Systems and Related Topics -,"
    March 2-3, 2013, ISIT, Fukuoka, Japan.
    [slide]

  • Shigeo Tsujii, Kohtaro Tadaki, Ryo Fujita, Hiroshi Yamaguchi,
    Masahito Gotaishi, Yukiyasu Tsunoo, Takahiko Syouji, and Norihisa Doi:
    Scheme overcoming incompatibility of privacy and utilization of personal data,
    Proceedings of 2012 International Symposium on Information Theory and its Applications (ISITA2012),
    pp.727-730, October 28-31, 2012, Honolulu, Hawaii, USA.

  • Ryo Fujita and Shigeo Tsujii:
    A study on practical use of computing on encrypted data and secure distributed computation,
    Japan Society of Security Management (JSSM) 26th national convention,
    June 23, 2012, The University of Electro-Communications, Tokyo, Japan. (In Japanese)

  • Ryo Fujita:
    Security analysis of multivariate public key cryptosystems using Gröbner bases,
    Workshop of Algebraic Geometry in Kyushu for Young Researchers,
    March 12-14, 2012, Faculty of Mathematics, Kyushu University, Fukuoka, Japan. (In Japanese)
    [slide (in Japanese)]

  • Ryo Fujita:
    Toward popularization of technologies for "Aggressive" secure distributed computation,
    Japan Society of Security Management (JSSM) 25th national convention,
    June 25-26, 2011, Nagaoka University of Technology, Niigata, Japan. (In Japanese)

  • Ryo Fujita:
    Cryptanalysis using Gröbner basis with Magma -- Algebraic attack against multivariate public key cryptosystems --,
    Exploring Mathematics with Magma,
    October 9-10, 2010, Faculty of Mathematics, Kyushu University, Fukuoka, Japan. (In Japanese)
    [report (in Japanese)] [slide (in Japanese)]

  • Masahito Gotaishi, Kohtaro Tadaki, Ryo Fujita, and Shigeo Tsujii:
    Dually-perturbed Matsumoto-Imai signature (DPMS) scheme,
    IEICE Trans. Fundamentals, Vol.E93-A, No.6, pp.1078-1085, June 2010.
    https://doi.org/10.1587/transfun.E93.A.1078

  • Shigeo Tsujii, Masahito Gotaishi, Kohtaro Tadaki, and Ryo Fujita:
    Proposal of a signature scheme based on STS trapdoor,
    Proceedings of the Third International Workshop on Post-Quantum Cryptography (PQCrypto 2010),
    Lecture Notes in Computer Science, Springer-Verlag, Vol.6061, pp.201-217, May 25-28, 2010, Darmstadt, Germany.
    [preprint: http://eprint.iacr.org/2010/118]

  • Ryo Fujita:
    Security analysis of rSTS type multivariate public key cryptosystems against algebraic attack using Gröbner bases,
    Recent Results Session at the third international workshop on Post-Quantum Cryptography (PQCrypto 2010),
    May 25-28, 2010, Darmstadt, Germany.
    [preliminary version (in Japanese)] [slide]

  • Ryo Fujita:
    Recent trends in research on multivariate public key cryptosystems,
    The 28th Meeting for Hot topics on Information Security Study,
    January 5, 2010, Japan Advanced Institute of Science and Technology (JAIST), Ishikawa, Japan. (In Japanese)

  • Shigeo Tsujii, Kohtaro Tadaki, Ryou Fujita, Masahito Gotaishi, and Toshinobu Kaneko:
    Security enhancement of various MPKCs by 2-layer nonlinear piece in hand method,
    IEICE Trans. Fundamentals, Vol.E92-A, No.10, pp.2438-2446, October 2009.
    https://doi.org/10.1587/transfun.E92.A.2438
    [preprint: http://eprint.iacr.org/2009/061]

  • Shigeo Tsujii, Kohtaro Tadaki, Masahito Gotaishi, Ryo Fujita, and Masao Kasahara:
    Proposal of PPS multivariate public key cryptosystems,
    Cryptology ePrint Archive, Report 2009/264, June 2009.
    http://eprint.iacr.org/2009/264

  • Ryo Fujita:
    A study on security of multivariate public key cryptosystems,
    Ph. D. Thesis, Institute of Information Security, March 2009. (In Japanese)
    [abstract (Japanese/English)] [pdf (in Japanese)]

  • Ryou Fujita, Kohtaro Tadaki, and Shigeo Tsujii:
    Nonlinear piece in hand perturbation vector method for enhancing security of multivariate public key cryptosystems,
    Proceedings of the Second International Workshop on Post-Quantum Cryptography (PQCrypto 2008),
    Lecture Notes in Computer Science, Springer-Verlag, Vol.5299, pp.148-164, October 17-19, 2008, University of Cincinnati, USA.
    https://doi.org/10.1007/978-3-540-88403-3_11
    [preliminary version (in Japanese)] [preprint: http://eprint.iacr.org/2008/298] [slide]

  • Shigeo Tsujii, Kohtaro Tadaki, and Ryou Fujita:
    Nonlinear piece in hand matrix method for enhancing security of multivariate public key cryptosystems,
    Proceedings of the First International Conference on Symbolic Computation and Cryptography (SCC 2008), pp.124-144,
    April 28-30, 2008, Beijing, China.
    [preprint: http://eprint.iacr.org/2008/077]

  • Shigeo Tsujii, Kohtaro Tadaki, and Ryou Fujita:
    Proposal for piece in hand matrix: General concept for enhancing security of multivariate public key cryptosystems,
    IEICE Trans. Fundamentals, Vol.E90-A, No.5, pp.992-999, May 2007.
    https://doi.org/10.1093/ietfec/e90-a.5.992

  • Shigeo Tsujii, Kohtaro Tadaki, and Ryou Fujita,
    Proposal for piece in hand matrix ver. 2: General concept for enhancing security of multivariate public key cryptosystems,
    Workshop Record of the International Workshop on Post-Quantum Cryptography (PQCrypto 2006), pp. 103-117,
    May 23-26, 2006, Leuven, Belgium.
    [preprint: http://eprint.iacr.org/2006/051]

  • Ryo Fujita:
    Effectiveness of Piece In Hand concept for enhancing the security of multivariate type public key cryptosystems,
    Master's Thesis, Department of Management Science, Graduate School of Engineering, Tokyo University of Science, March 2006. (In Japanese)
    [abstract (in Japanese)] [pdf (in Japanese)]

  • Shigeo Tsujii, Kohtaro Tadaki, and Ryou Fujita:
    Piece in hand concept for enhancing the security of multivariate type public key cryptosystems:
    Public key without containing all the information of secret key,
    Cryptology ePrint Archive, Report 2004/366, December 2004.
    http://eprint.iacr.org/2004/366

Membership

  • Member of the Institute of Electronics, Information and Communication Engineers (IEICE)
  • Representative of Japan Society of Security Management (JSSM)
  • Member of the International Association for Cryptologic Research (IACR)

Copyright (c) 2011-2018 Ryo Fujita All Rights Reserved.

This website is maintained by Ryo Fujita.
Last-Modified: 07/24/2018


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