Ryo Nishimaki

Cryptographer
@NTT, Japan
[DBLP], [Google Scholar]

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Preprints

  1. Constrained PRFs for $\textbf{NC}^1$ in Traditional Groups
    Nuttapong Attrapadung, Takahiro Matsuda, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa
    ePrint archive » eprint
  2. From Single-Key to Collusion-Resistant Secret-Key Functional Encryption by Leveraging Succinctness
    Fuyuki Kitagawa, Ryo Nishimaki, Keisuke Tanaka
    ePrint archive » eprint
  3. Indistinguishability Obfuscation for All Circuits from Secret-Key Functional Encryption
    Fuyuki Kitagawa, Ryo Nishimaki, Keisuke Tanaka
    ePrint archive » eprint

International Conferences

    2018

  1. Obfustopia built on Secret-Key Functional Encryption
    Fuyuki Kitagawa, Ryo Nishimaki, Keisuke Tanaka
    Eurocrypt 2018 (LNCS 10821, to appear) » eprint and eprint
  2. Simple and Generic Constructions of Succinct Functional Encryption
    Fuyuki Kitagawa, Ryo Nishimaki, Keisuke Tanaka
    PKC 2018 (LNCS 10770) » eprint
  3. 2017

  4. Compact Structure-preserving Signatures with Almost Tight Security
    Masayuki Abe, Dennis Hofheinz, Ryo Nishimaki, Miyako Ohkubo, Jiaxin Pan
    CRYPTO 2017 (LNCS 10402) » eprint acceptance rate = 72/311 = 23.2%
  5. 2016

  6. From Cryptomania to Obfustopia through Secret-Key Functional Encryption
    Nir Bitansky, Ryo Nishimaki, Alain Passelègue, Daniel Wichs
    TCC 2016B (LNCS 9986) » eprint
  7. Watermarking Cryptographic Capabilities
    Aloni Cohen, Justin Holmgren, Ryo Nishimaki, Vinod Vaikuntanathan, Daniel Wichs
    STOC 2016 (ACM) » eprint
    This is a merged version of [NW15] and [CHV15] with additional results. acceptance rate = 92/370 = 24.9%
  8. Anonymous Traitor Tracing: How to Embed Arbitrary Information in a Key
    Ryo Nishimaki, Daniel Wichs, Mark Zhandry
    Eurocrypt 2016 (LNCS 9666) » eprint acceptance rate = 62/274 = 22.6%
  9. 2015

  10. Generalizing Efficeint Multiparty Computation
    Bernardo David, Ryo Nishimaki, Samuel Ranellucci, Alain Tapp
    ICITS 2015 (LNCS 9063) » eprint
  11. 2014

  12. Re-Encryption, Functional Re-Encryption, and Multi-Hop Re-Encryption: A Framework for Achieving Obfuscation-Based Security and Instantiations from Lattices
    Nishanth Chandran, Melissa Chase, Feng-Hao Liu, Ryo Nishimaki, Keita Xagawa
    PKC 2014 (LNCS 8383) » eprint
  13. 2013

  14. Universally Composable Adaptive Oblivious Transfer with Access Control from Standard Assumptions
    Masayuki Abe, Jan Camenisch, Maria Dubovitskaya, Ryo Nishimaki
    ACM Digital Identity Management 2013 (ACM press)
  15. How to Watermark Cryptographic Functions
    Ryo Nishimaki
    Eurocrypt 2013 (LNCS 7881) » eprint acceptance rate = 41/202 = 20%
  16. Verifiably Encrypted Signatures with Short Keys based on the Decisional Linear Problem and Obfuscation for Encrypted VES
    Ryo Nishimaki, Keita Xagawa
    PKC 2013 (LNCS 7778) » eprint acceptance rate = 28/97 = 29%
  17. Tagged One-Time Signatures: Tight Security and Optimal Tag Size
    Masayuki Abe, Bernardo David, Markulf Kohlweiss, Ryo Nishimaki, Miyako Ohkubo
    PKC 2013 (LNCS 7778) » eprint acceptance rate = 28/97 = 29%
  18. 2012

  19. Constant-Size Structure-Preserving Signatures: Generic Constructions and Simple Assumptions
    Masayuki Abe, Melissa Chase, Bernardo David, Markulf Kohlweiss, Ryo Nishimaki, Miyako Ohkubo
    Asiacrypt 2012 (LNCS 7658) » eprint
    acceptance rate = 43/247 = 17% Invited to Journal of Cryptology
  20. 2010

  21. A Multi-trapdoor Commitment Scheme from the RSA Assumption
    Ryo Nishimaki, Eiichiro Fujisaki, Keisuke Tanaka
    ACISP 2010 (LNCS 6168)
  22. CCA Proxy Re-Encryption without Bilinear Maps in the Standard Model
    Toshihide Matsuda, Ryo Nishimaki, Keisuke Tanaka
    PKC 2010 (LNCS 6056)
    Subsequent to the publication of the above work, it was pointed out that the security proof is incorrect. See "On the Security of a Bidirectional Proxy Re-encryption Scheme from PKC 2010" in PKC 2011 for details.
  23. 2009

  24. On the Insecurity of the Fiat-Shamir Signatures with Iterative Hash Functions
    Eiichiro Fujisaki, Ryo Nishimaki, Keisuke Tanaka
    ProvSec 2009 (LNCS 5848)
  25. Efficient Non-interactive Universally Composable String-Commitment Schemes
    Ryo Nishimaki, Eiichiro Fujisaki, Keisuke Tanaka
    ProvSec 2009 (LNCS 5848)
  26. Security on Hybrid Encryption with the Tag-KEM/DEM Framework
    Toshihide Matsuda, Ryo Nishimaki, Akira Numayama, Keisuke Tanaka
    ACISP 2009 (LNCS 5594)
  27. 2006

  28. Universally Composable Identity-Based Encryption
    Ryo Nishimaki, Yoshifumi Manabe, Tatsuaki Okamoto
    VIETCRYPT 2006 (LNCS 4341)

Journal Articles

  1. Constant-Size Structure-Preserving Signatures: Generic Constructions and Simple Assumptions
    Masayuki Abe, Melissa Chase, Bernardo David, Markulf Kohlweiss, Ryo Nishimaki, Miyako Ohkubo
    Journal of Cryptology 29(4): 833-878
  2. Verifiably Encrypted Signatures with Short Keys based on the Decisional Linear Problem and Obfuscation for Encrypted VES
    Ryo Nishimaki, Keita Xagawa
    Designs, Codes and Cryptography 77(1): 61-98
  3. Post-Challenge Leakage Resilient Public-Key Cryptosystem in Split State Model
    Eiichiro Fujisaki, Akinori Kawachi, Ryo Nishimaki, Keisuke Tanaka, and Kenji Yasunaga
    IEICE Transactions E98-A(3)
  4. Key-Private Proxy Re-Encryption from Lattices, Revisited
    Ryo Nishimaki, Keita Xagawa
    IEICE Transactions E98-A(1)
  5. An Efficient Non-interactive Universally Composable String-Commitment Scheme
    Ryo Nishimaki, Eiichiro Fujisaki, Keisuke Tanaka
    IEICE Transactions E95-A(1)
  6. A Multi-Trapdoor Commitment Scheme from the RSA Assumption
    Ryo Nishimaki, Eiichiro Fujisaki, Keisuke Tanaka
    IEICE Transactions E95-A(1)
  7. Universally Composable Identity-Based Encryption
    Ryo Nishimaki, Yoshifumi Manabe, Tatsuaki Okamoto
    IEICE Transactions E91-A(1)

Invited Papers

  1. Watermarking Cryptographic Programs (Survey paper)
    Ryo Nishimaki
    Mycrypt 2016 (LNCS 10311)

PhD Thesis

Unpublished Manuscripts

  1. Watermarking Cryptographic Programs Against Arbitrary Removal Strategies
    Ryo Nishimaki, Daniel Wichs
    Most of the results in this paper are superseded by [CHN+16]

Books

  1. Theory of Public-Key Cryptography (in Japanese)
    Moriyama Daisuke, Ryo Nishimaki, Tatsuaki Okamoto
    The Japan Society for Industrial and Applied Mathematics (JSAIM) (Editor)
    KYORITSU SHUPPAN CO., LTD. (Publisher)
    Mar. 2011.

    Errata » pdf