Takashi Yamakawa
(山川高志)
I am a researcher at NTT, Japan. My main research area is (post-quantum) cryptography.
I am visiting Princeton University until April 2021 hosted by Prof. Mark Zhandry
Bio.
Jan. 2020-present: Visiting Scholar at Princeton University
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
The order of authors is alphabetical, unless otherwise noted.
(Most works done in 2016 or earlier use non-alphabetical order, and the others use alphabetical order. )
Preprint
A Black-Box Approach to Post-Quantum Zero-Knowledge in Constant Rounds. Nai-Hui Chia, Kai-Min Chung, Takashi Yamakawa, arXiv ePrint
Secure Software Leasing from Standard Assumptions. Fuyuki Kitagawa, Ryo Nishimaki, Takashi Yamakawa, arXiv ePrint
International Conferences
Round-Optimal Blind Signatures in the Plain Model from Classical and Quantum Standard Assumptions. Shuichi Katsumata, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa, Eurocrypt 2021.
Classical vs Quantum Random Oracles. Takashi Yamakawa, Mark Zhandry, Eurocrypt 2021. ePrint
(Preliminary version appeared as A Note on Separating Classical and Quantum Random Oracles. ePrint)Adaptively Secure Inner Product Encryption from LWE. Shuichi Katsumata, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa, Asiacrypt 2020. ePrint
Finding Collisions in a Quantum World: Quantum Black-Box Separation of Collision-Resistance and One-Wayness. Akinori Hosoyamada, Takashi Yamakawa, Asiacrypt 2020. (Best Paper Award) ePrint
NIZK from SNARG. Fuyuki Kitagawa, Takahiro Matsuda, Takashi Yamakawa, TCC 2020. ePrint video
Classical Verification of Quantum Computations with Efficient Verifier. Nai-Hui Chia, Kai-Min Chung, Takashi Yamakawa, TCC 2020. arXiv ePrint video (by Nai-Hui Chia)
Adaptively Secure Constrained Pseudorandom Functions in the Standard Model. Alex Davidson, Shuichi Katsumata, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa, CRYPTO 2020. ePrint video
Compact NIZKs from Standard Assumptions on Bilinear Maps. Shuichi Katsumata, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa, Eurocrypt 2020. ePrint video (by Shuichi Katsumata)
Quantum Random Oracle Model with Auxiliary Input. Minki Hhan, Keita Xagawa, Takashi Yamakawa, Asiacrypt 2019. ePrint
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. ePrint video (by Shuichi Katsumata)
Designated Verifier/Prover and Preprocessing NIZKs from Diffie-Hellman Assumptions. Shuichi Katsumata, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa, Eurocrypt 2019. ePrint video (by Shuichi Katsumata)
(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 video
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 (non-alphabetical order), ACISP 2016.
Adversary-Dependent Lossy Trapdoor Function from Hardness of Factoring Semi-smooth RSA Subgroup Moduli. Takashi Yamakawa, Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro (non-alphabetical order), CRYPTO 2016. ePrint video
A Short Fail-Stop Signature Scheme from Factoring. Takashi Yamakawa, Nobuaki Kitajima, Takashi Nishide, Goichiro Hanaoka, Eiji Okamoto (non-alphabetical order), 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 (non-alphabetical order), SCN 2014.
Self-bilinear Map on Unknown Order Groups from Indistinguishability Obfuscation and Its Applications. Takashi Yamakawa, Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro (non-alphabetical order), CRYPTO 2014. (Invited to Special Issues of Algorithmica.) ePrint video
Reducing Public Key Sizes in Bounded CCA-Secure KEMs with Optimal Ciphertext Length. Takashi Yamakawa, Shota Yamada, Takahiro Matsuda, Goichiro Hanaoka, Noboru Kunihiro (non-alphabetical order), 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 (non-alphabetical order), 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 (non-alphabetical order), AsiaPKC 2013.
Journal Articles
Tighter Security Proofs for GPV-IBE in the Quantum Random Oracle Model. Shuichi Katsumata, Shota Yamada, Takashi Yamakawa, Journal of Cryptology, Volume 34, 2021. ePrint
Generic Hardness of Inversion on Ring and Its Relation to Self-Bilinear Map. Takashi Yamakawa, Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro (non-alphabetical order), Theoretical Computer Science 820, 2020 ePrint
Self-Bilinear Map on Unknown Order Groups from Indistinguishability Obfuscation and Its Applications. Takashi Yamakawa, Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro (non-alphabetical order) Algorithmica 79(4), 2017. 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 (non-alphabetical order) IEICE Transactions 100-A(9), 2017.
Efficient Key Encapsulation Mechanisms with Tight Security Reductions to Standard Assumptions in the Two Security Models. Yoshikazu Hanatani, Goichiro Hanaoka, Takahiro Matsuda, Takashi Yamakawa (non-alphabetical order), Security and Communication Networks 9(12), 2016.
Posters
Bounded CCA-Secure KEM from the Computational Bilinear Diffie-Hellman Assumption. Takashi Yamakawa, Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro (non-alphabetical order) IWSEC 2012. (Best Poster Award)
Talks
NIZK from SNARG
TCC 2020, online, November 2020.
UC Berkeley Crypto Seminar, online, August 2020.
Adaptively Secure Constrained Pseudorandom Functions in the Standard Model.
CRYPTO 2020, online, August 2020.
Introduction to post-quantum public key cryptography and zero-knowledge. (耐量子公開鍵暗号入門・耐量子ゼロ知識証明入門)
The 3rd YITP Quantum Information School (第三回基研量子情報スクール), online, July 2020. (In Japanese)
Finding Collisions in a Quantum World: Quantum Black-Box Separation of Collision-Resistance and One-Wayness.
Joint Workshop of NTT Labs (Japan) and NTT Research (USA), Kyoto, December 2019.
Theory Day in Taiwan (2019), Taipei, October 2019.
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 (Invited)
Tightly-Secure Key-Encapsulation Mechanism in the Quantum Random Oracle Model.
Eurocrypt 2018, Tel Aviv, May 2018
ISEC Seminar, Sapporo, July 2018 (In Japanese)
Constrained PRFs for NC1 in Traditional Groups.
Tokyo Crypto Day, Tokyo, March. 2018
CRYPTO 2018, Santa Barbara, Aug. 2018
ISEC Seminar, Tokyo, Sep. 2018 (In Japanese)
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 (In Japanese)
10-th Workshop on Secure Constructions and Applications of Public Key Cryptography, Tokyo, Feb. 2017 (In Japanese)
Generalized Hardness Assumption for Self-bilinear Map with Auxiliary Information.
ACISP 2016, Melbourne, July 2016
Applications of Indistinguishability Obfuscation. (識別不可性難読化の応用)
IEICE General Conference, Shiga, Mar. 2015 (In Japanese)
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 (In Japanese)
8-th Workshop on Secure Constructions and Applications of Public Key Cryptography, Tokyo, Feb. 2015 (In Japanese)
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 (Invited)
Activities
Program Committee Member: APKC 2019, APKC 2018
Subreviewer: Asiacrypt, CRYPTO, Eurocrypt, PKC, TCC, ACISP, ACNS, ISITA, IWSEC, Provsec, SCN, etc.
Awards
Asiacrypt 2020 Best Paper Award
for the paper: Finding Collisions in a Quantum World: Quantum Black-Box Separation of Collision-Resistance and One-Wayness (with Akinori Hosoyamada).
Dean's Award for Outstanding Achievement from Graduate School of Frontier Science (Ph.D) (top honor in the department), The University of Tokyo, March 2017.
Tsujii Shigeo Security Student Award, 2015.
for the paper: Self-bilinear Map on Unknown Order Groups from Indistinguishability Obfuscation and Its Applications (with Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro, CRYPTO 2014).
Dean's Award for Outstanding Achievement from Graduate School of Frontier Science (Master) (top honor in the department), The University of Tokyo, March 2014.
SCIS Paper Award at SCIS 2013 (Japanese domestic conference).
for the paper: 素因数分解問題に基づくSemi-smooth部分群上のCCA安全な公開鍵暗号の安全性証明について (On Security Proof of CCA-Secure Public Key Encryption in Semi-Smooth Subgroups) (with Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro)
IWSEC 2012 Best Poster Award.
for the poster: Bounded CCA-Secure KEM from the Computational Bilinear Diffie-Hellman Assumption (with Shota Yamada, Goichiro Hanaoka, Noboru Kunihiro)
Hobbies
Othello: A two-player strategy board game popular in Japan, I've been playing since 2002. I'm currently ranked 5th at World Othello Federation Ratings (Apr. 2020).
You can learn the rule and basic strategies from a free e-book written by a former world champion Brian Rose here.I'm also a fan of other board games including Go, Shogi (Japanese Chess), Backgammon etc.
Contact Information
Please send official invitation emails (PC member, talks, etc. ) to: takashi.yamakawa.ga@hco.ntt.co.jp
For other emails (review request, question/comment on paper, etc.): takashi.yamakawa.obf@gmail.com