Atsushi Takayasu

I am an assistant professor in the University of Tokyo, Graduate School of Information Science and Technology, Department of Mathematical Informatics.

I am a member of Mathematical Informatics 1st Laboratory.

My research interest is cryptography, especially lattices, lattice reductions, and cryptanalysis.

See dblp, google scholar citations.

Mathematical Informatics 1st Laboratory, Faculty of Engineering Bldg. #6, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, JAPAN

e-mail: takayasu[at]mist.i.u-tokyo.ac.jp

tel: +81-3-5841-6914

  • Bachelor of Engineering from Mathematical Engineering Course, Department of Mathematical Engineering and Information Physics, Faculty of Engineering, The University of Tokyo, March 2012.
  • Master of Science from Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo, March 2014. (Supervisor, Noboru Kunihiro)
  • JSPS Research Fellowship for Young Scientists (DC1), April 2014 - March 2017.
  • Collaborative Researcher in National Institute of Advanced Industrial Science and Technology (AIST), April 2015 - Now.
  • Ph.D of Science from Department of Complexity Science and Engineering, Graduate School of Frontier Sciences, The University of Tokyo, March 2017. (Supervisor, Noboru Kunihiro)
  • Assistant professor in the University of Tokyo, Graduate School of Information Science and Technology, Department of Mathematical Informatics, April 2017 - Now.

Refereed International Journal

  1. A. Takayasu and N. Kunihiro. Partial Key Exposure Attacks on RSA: Achieving the Boneh-Durfee Bound. Theoretical Computer Science.
  2. A. Takayasu, Y. Lu, and L. Peng. Small CRT-exponent RSA Revisited. Journal of Cryptology, 2018.
  3. A. Takayasu and N. Kunihiro. General Bounds for Small Inverse Problems and Its Applications to Multi-Prime RSA. IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol. E100-A, No. 1, pp. 50-61, 2017.
  4. A. Takayasu and N. Kunihiro. Better Lattice Constructions for Solving Multivariate Linear Equations Modulo Unknown Divisors. IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, Vol. E97-A, No. 6, pp. 1259-1272, 2014.

Refereed International Conference Proceeding

  1. H. Okada, A. Takayasu, K. Fukushima, S. Kiyomoto, and T. Takagi. On the complexity of the LWR-Solving BKW Algorithm. ICISC 2018.
  2. W. Wang, Y. Wang, A. Takayasu, and T. Takagi. Estimated Cost for Solving Generalized Learning with Errors Problem via Embedding Techniques. Proc. IWSEC 2018, Springer, 2018. (presented by the first author, the first author received Best Student Paper Award)
  3. A. Takayasu and Y. Watanabe. Lattice-based Revocable Identity-based Encryption with Bounded Decryption Key Exposure Resistance. Proc. ACISP 2017, LNCS 10342, pp. 184-204, Springer, 2017. [ePrint]
  4. A. Takayasu, Y. Lu, and L. Peng. Small CRT-exponent RSA Revisited. Proc. Eurocrypt 2017, LNCS 10211, pp. 130-159, Springer, 2017. [ePrint]
  5. A. Takayasu and N. Kunihiro. A Tool Kit for Partial Key Exposure Attacks on RSA. Proc. CT-RSA 2017, LNCS 10159, pp. 58-73, Springer, 2017. [ePrint]
  6. A. Takayasu and N. Kunihiro. Small Secret Exponent Attacks on RSA with Unbalanced Prime Factors. Proc. ISITA 2016, pp. 236-240, IEEE, 2016.
  7. A. Takayasu and N. Kunihiro. Partial Key Exposure Attacks on CRT-RSA: General Improvement for the Exposed Least Significant Bits. Proc. ISC 2016, LNCS 9866, pp. 35-47, Springer, 2016.
  8. A. Takayasu and N. Kunihiro. Partial Key Exposure Attacks on RSA with Multiple Exponent Pairs. Proc. ACISP 2016, LNCS 9723, pp. 243-257, Springer, 2016. (Best Student Paper Award)
  9. A. Takayasu and N. Kunihiro. How to Generalize RSA Cryptanalyses. Proc. PKC 2016, LNCS 9615, pp. 67-97, Springer 2016. [ePrint]
  10. K. Takashima and A. Takayasu. Tighter Security for Efficient Lattice Cryptography via the Renyi Divergence of Optimized Orders. Proc. ProvSec 2015, LNCS 9451, pp. 412-431, Springer, 2015. [ePrint]
  11. A. Takayasu and N. Kunihiro. Partial Key Exposure Attacks on CRT-RSA: Better Cryptanalysis to Full Size Encryption Exponents. Proc. ACNS 2015, LNCS 9092, pp. 518-537, Springer, 2015.
  12. A. Takayasu and N. Kunihiro. General Bounds for Small Inverse Problems and Its Applications to Multi-Prime RSA. Proc. ICISC 2014, LNCS 8949, pp. 3-17, Springer, 2014. [ePrint]
  13. A. Takayasu and N. Kunihiro. Partial Key Exposure Attacks on RSA: Achieving the Boneh-Durfee Bound. Proc. SAC 2014, LNCS 8781, pp. 345-362, Springer, 2014. [ePrint]
  14. A. Takayasu and N. Kunihiro. Cryptanalysis of RSA with Multiple Small Secret Exponents. Proc. ACISP 2014, LNCS 8544, pp. 176-191, Springer 2014.
  15. A. Takayasu and N. Kunihiro. Better Lattice Constructions for Solving Multivariate Linear Equations Modulo Unknown Divisors. Proc. ACISP 2013, LNCS 7959, pp. 118-135, Springer, 2013.

Other International Conference Talks

  1. K. Matsuda, A. Takayasu, and T. Takagi. Explicit Relation between Low-dimensional LLL-reduced Bases and the Shortest Vectors. AAAC2018, 2018. (presented by the first author)
  2. A. Takayasu. Parameter Selections for Approximate GCD Problems. SCIS/CSS Invited Session in IWSEC 2016, 2016.
  3. A. Takayasu and N. Kunihiro. Faster LLL Reduction to Break the Security of Fully Homomorphic Encryption and Multilinear Map over the Integers. Poster session in IWSEC 2015, 2015.
  4. A. Takayasu. Improved Algorithms for Partial Key Exposure Attacks on RSA. SCIS/CSS Invited Session in IWSEC 2014, 2014.
  5. A. Takayasu and N. Kunihiro. Partial Key Exposure Attacks on RSA When Most Significant Bits of d Known. Poster session in ACM ASIACCS 2014, 2014.
  6. A. Takayasu and N. Kunihiro. Partial Key Exposure Attacks on RSA: Achieve Boneh-Durfee's Bound. Poster session in IWSEC 2013, 2013.

Other Talks

  1. Solving RSA and Factoring Problems Using LLL Reduction. Workshop on analysis of mathematical cryptography via algebraic methods,February 2018.
  2. Small CRT-exponent RSA Revisited. NTT-JFLI-U.Tokyo Workshop on Cryptography, January 2018.
  3. Small CRT-exponent RSA Revisited. Tokyo Crypto Day, June 2017.

Professional Activities