Takashi Yamakawa (山川高志)

Email: takashi.yamakawa.ga(at)hco.ntt.co.jp

I am a researcher at NTT, Japan. My main research area is cryptography.


Bio.

  • Apr. 2017-present: Researcher at NTT
  • Mar. 2017 Ph.D in Science from The University of Tokyo (Supervisor: Prof. Noboru Kunihiro)
  • Apr. 2014-Mar. 2017: JSPS Research Fellowship for Young Scientists (DC1)
  • Apr. 2016-Mar. 2017 Collaborative Researcher at National Institute of Advanced Industrial Science and Technology (AIST)
  • Mar. 2014 Master of Science from The University of Tokyo (Supervisor: Prof. Noboru Kunihiro)
  • Aug. 2012-Mar. 2014: Technical Staff at National Institute of Advanced Industrial Science and Technology (AIST)
  • Mar. 2012 Bachelor of Science from The University of Tokyo (Major: Mathematics)


Publications

See also DBLP and Google Scholar

International Conferences

  • Adaptively Secure and Succinct Functional Encryption: Improving Security and Efficiency, Simultaneously, Fuyuki Kitagawa, Ryo Nishimaki , Keisuke Tanaka, Takashi Yamakawa, CRYPTO 2019. ePrint
  • Exploring Constructions of Compact NIZKs from Various Assumptions. Shuichi Katsumata, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa, CRYPTO 2019.
  • Designated Verifier/Prover and Preprocessing NIZKs from Diffie-Hellman Assumptions. Shuichi Katsumata, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa, Eurocrypt 2019. ePrint
  • (Tightly) QCCA-Secure Key-Encapsulation Mechanism in the Quantum Random Oracle Model. Keita Xagawa, Takashi Yamakawa, PQCrypto 2019. ePrint
  • Leakage-resilient Identity-based Encryption in Bounded Retrieval Model with Nearly Optimal Leakage-Ratio. Ryo Nishimaki, Takashi Yamakawa, PKC 2019. ePrint
  • Adaptively Single-key Secure Constrained PRFs for NC1. Nuttapong Attrapadung, Takahiro Matsuda, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa, PKC 2019. ePrint
  • Tighter Security Proofs for GPV-IBE in the Quantum Random Oracle Model. Shuichi Katsumata, Shota Yamada, Takashi Yamakawa, ASIACRYPT 2018. (Invited to Journal of Cryptology.) ePrint
  • Constrained PRFs for NC1 in Traditional Groups. Nuttapong Attrapadung, Takahiro Matsuda, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa, CRYPTO 2018. ePrint
  • Tightly-Secure Key-Encapsulation Mechanism in the Quantum Random Oracle Model. Tsunekazu Saito, Keita Xagawa, Takashi Yamakawa, EUROCRYPT 2018. ePrint
  • Generalized Hardness Assumption for Self-bilinear Map with Auxiliary Information. Takashi Yamakawa, Goichiro Hanaoka, Noboru Kunihiro, ACISP 2016.
  • Adversary-Dependent Lossy Trapdoor Function from Hardness of Factoring Semi-smooth RSA Subgroup Moduli. Takashi Yamakawa, Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro, CRYPTO 2016. ePrint
  • A Short Fail-Stop Signature Scheme from Factoring. Takashi Yamakawa, Nobuaki Kitajima, Takashi Nishide, Goichiro Hanaoka, Eiji Okamoto, ProvSec 2014.
  • Chosen Ciphertext Security on Hard Membership Decision Groups: The Case of Semi-smooth Subgroups of Quadratic Residues. Takashi Yamakawa, Shota Yamada, Koji Nuida, Goichiro Hanaoka, Noboru Kunihiro, SCN 2014.
  • Self-bilinear Map on Unknown Order Groups from Indistinguishability Obfuscation and Its Applications. Takashi Yamakawa, Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro, CRYPTO 2014. (Invited to Algorithmica.) ePrint
  • Reducing Public Key Sizes in Bounded CCA-Secure KEMs with Optimal Ciphertext Length. Takashi Yamakawa, Shota Yamada, Takahiro Matsuda, Goichiro Hanaoka, Noboru Kunihiro, ISC 2013.
  • Partially Wildcarded Attribute-based Encryption and Its Efficient Construction. Go Ohtake, Yuki Hironaka, Kenjiro Kai, Yosuke Endo, Goichiro Hanaoka, Hajime Watanabe, Shota Yamada, Kohei Kasamatsu, Takashi Yamakawa, Hideki Imai, SECRYPT 2013.
  • Efficient Variants of the Naor-Yung and Dolev-Dwork-Naor Transforms for CCA Secure Key Encapsulation Mechanism. Takashi Yamakawa, Shota Yamada, Takahiro Matsuda, Goichiro Hanaoka, Noboru Kunihiro, AsiaPKC 2013.

Journal Articles

  • Self-Bilinear Map on Unknown Order Groups from Indistinguishability Obfuscation and Its Applications. Takashi Yamakawa, Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro Algorithmica 79(4). ePrint
  • Partially Wildcarded Ciphertext-Policy Attribute-Based Encryption and Its Performance Evaluation. Go Ohtake, Kazuto Ogawa, Goichiro Hanaoka, Shota Yamada, Kohei Kasamatsu, Takashi Yamakawa, Hideki Imai IEICE Transactions 100-A(9).
  • Efficient Key Encapsulation Mechanisms with Tight Security Reductions to Standard Assumptions in the Two Security Models. Yoshikazu Hanatani, Goichiro Hanaoka, Takahiro Matsuda, Takashi Yamakawa Security and Communication Networks 9(12).

Posters

  • Bounded CCA-Secure KEM from the Computational Bilinear Diffie-Hellman Assumption. Takashi Yamakawa, Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro IWSEC 2012. (Best Poster Award)

Manuscripts

  • Finding Collisions in a Quantum World: Quantum Black-Box Separation of Collision-Resistance and One-Wayness. Akinori Hosoyamada, Takashi Yamakawa, ePrint
  • Generic Hardness of Inversion on Ring and Its Relation to Self-Bilinear Map, Takashi Yamakawa, Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro, ePrint


Talks

  • Adaptively Single-key Secure Constrained PRFs for NC1.
    • PKC 2019, Beijing, April 2019
  • Leakage-resilient Identity-based Encryption in Bounded Retrieval Model with Nearly Optimal Leakage-Ratio.
    • PKC 2019, Beijing, April 2019
  • Towards Ideal Self-bilinear Map.
    • The 5th ACM ASIA Public-Key Cryptography Workshop, June 2018
  • Tightly-Secure Key-Encapsulation Mechanism in the Quantum Random Oracle Model.
    • Eurocrypt 2018, Tel Aviv, May 2018
    • ISEC Seminar, Sapporo, July 2018
  • Constrained PRFs for NC1 in Traditional Groups.
    • Tokyo Crypto Day, Tokyo, March. 2018
    • CRYPTO 2018, Santa Barbara, Aug. 2018
    • ISEC Seminar, Tokyo, Sep. 2018
  • Adversary-dependent Lossy Trapdoor Function from Hardness of Factoring Semi-smooth RSA Subgroup Moduli.
    • CRYPTO 2016, Santa Barbara, Aug. 2016
    • ISEC Seminar, Hiroshima, Dec. 2016
    • 10-th Workshop on Secure Constructions and Applications of Public Key Cryptography, Tokyo, Feb. 2017
  • Generalized Hardness Assumption for Self-bilinear Map with Auxiliary Information.
    • ACISP 2016, Melbourne, July 2016
  • Applications of Indistinguishability Obfuscation.
    • IEICE General Conference, Shiga, Mar. 2015
  • A Short Fail-Stop Signature Scheme from Factoring.
    • ProvSec 2014, Hong Kong, Oct. 2014
  • Chosen Ciphertext Security on Hard Membership Decision Groups: The Case of Semi-smooth Subgroups.
    • SCN 2014, Amalfi, Sep. 2014
  • Self-bilinear Map on Unknown Order Groups from Indistinguishability Obfuscation and Its Applications.
    • CRYPTO 2014, Santa Barbara, Aug. 2014
    • ISEC Seminar, Tokyo, Dec. 2014
    • 8-th Workshop on Secure Constructions and Applications of Public Key Cryptography, Tokyo, Feb. 2015
  • Reducing Public Key Sizes in Bounded CCA-Secure KEMs with Optimal Ciphertext Length.
    • ISC 2013, Dallas, Nov. 2013
  • Chosen Ciphertext Secure Encryption over Semi-smooth Subgroup Revisited.
    • IWSEC 2013, SCIS/CSS Invited Session, Okinawa, Nov. 2013


Activities

Program Committee Member: APKC 2019, APKC 2018

Subreviewer: Asiacrypt, CRYPTO, Eurocrypt, PKC, TCC, ACISP, ACNS, ISITA, IWSEC, Provsec, SCN


Awards

  • Dean's Award for Outstanding Achievement from Graduate School of Frontier Science (Ph.D), The University of Tokyo, March 2017.
  • Tsujii Shigeo Security Student Award, 2015.
  • Dean's Award for Outstanding Achievement from Graduate School of Frontier Science (Master), The University of Tokyo, March 2014.
  • SCIS Paper Award at SCIS 2013.
  • IWSEC 2012 Best Poster Award.


Hobbies