Publications

See also my DBLP and Google Scholar pages.

Preprint


  • Constrained PRFs for Bit-fixing from OWFs with Constant Collusion-Resistance
    Alex Davidson, Shuichi Katsumata, Ryo Nishimaki, Shota Yamada
    ePrint archive » pdf
    This is a merged version of eprint:DavNis18 and eprint:KatYam18 with additional results.
  • Adaptively Secure and Succinct Functional Encryption: Improving Security and Efficiency, Simultaneously
    Fuyuki Kitagawa, Ryo Nishimaki, Keisuke Tanaka, Takashi Yamakawa
    ePrint archive » pdf
  • A Bit-fixing PRF with O(1) Collusion-Resistance from LWE
    Alex Davidson, Ryo Nishimaki
    ePrint archive » pdf
    This work was superseded by eprint:DKNY18.
  • Universal Proxy Re-Encryption
    Nico Döttling, Ryo Nishimaki
    ePrint archive » pdf
  • From Single-Key to Collusion-Resistant Secret-Key Functional Encryption by Leveraging Succinctness
    Fuyuki Kitagawa, Ryo Nishimaki, Keisuke Tanaka
    ePrint archive » pdf
    under submission to a journal
  • Indistinguishability Obfuscation for All Circuits from Secret-Key Functional Encryption
    Fuyuki Kitagawa, Ryo Nishimaki, Keisuke Tanaka
    ePrint archive » pdf
    under submission to a journal

Refereed Internarional Conferences


2018

  • Constrained PRF for NC1 in Traditional Groups
    Nuttapong Attrapadung, Takashiro Matsuda, Ryo Nishimaki, Shota Yamada, Takashi Yamakawa
    CRYPTO 2018 (LNCS 10992) » eprint ver
    acceptacnce rate = 79351 = 22.5%

  • Obfustopia built on Secret-Key Functional Encryption
    Fuyuki Kitagawa, Ryo Nishimaki, Keisuke Tanaka
    Eurocrypt 2018 (LNCS 10821) » proceedings ver
    Note: This is a hard merge version of eprint:KNT17b and eprintLKNT17c
    acceptacnce rate = 69294 = 23.5%

  • Simple and Generic Constructions of Succinct Functional Encryption
    Fuyuki Kitagawa, Ryo Nishimaki, Keisuke Tanaka
    PKC 2018 (LNCS 10770) » eprint ver
    acceptacnce rate = 49186 = 26.3%

2017

2016

2015

  • Generalizing Efficeint Multiparty Computation
    Bernardo David, Ryo Nishimaki, Samuel Ranellucci, Alain Tapp
    ICITS 2015 (LNCS 9063) » eprint ver
    acceptance rate = unknown

2014

2013

  • Universally Composable Adaptive Oblivious Transfer with Access Control from Standard Assumptions
    Masayuki Abe, Jan Camenisch, Maria Dubovitskaya, Ryo Nishimaki
    ACM Digital Identity Management 2013
    acceptance rate = unknown

  • How to Watermark Cryptographic Functions
    Ryo Nishimaki
    Eurocrypt 2013 (LNCS 7881) eprint ver
    acceptance rate = 41202 = 20%

  • 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) » IACR ver
    acceptance rate = 2897 = 29%

  • Tagged One-Time Signatures: Tight Security and Optimal Tag Size
    Masayuki Abe, Bernardo David, Markulf Kohlweiss, Ryo Nishimaki, Miyako Ohkubo
    PKC 2013 (LNCS 7778) » IACR ver
    acceptance rate = 2897 = 29%

2012

2010

  • A Multi-trapdoor Commitment Scheme from the RSA Assumption
    Ryo Nishimaki, Eiichiro Fujisaki, Keisuke Tanaka
    ACISP 2010 (LNCS 6168)
    acceptance rate = unknown

  • CCA Proxy Re-Encryption without Bilinear Maps in the Standard Model
    Toshihide Matsuda, Ryo Nishimaki, Keisuke Tanaka
    PKC 2010 (LNCS 6056)
    acceptance rate = unknown
    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.

2009

  • On the Insecurity of the Fiat-Shamir Signatures with Iterative Hash Functions
    Eiichiro Fujisaki, Ryo Nishimaki, Keisuke Tanaka
    ProvSec 2009 (LNCS 5848)
    acceptance rate = unknown

  • Efficient Non-interactive Universally Composable String-Commitment Schemes
    Ryo Nishimaki, Eiichiro Fujisaki, Keisuke Tanaka
    ProvSec 2009 (LNCS 5848)
    acceptance rate = unknown

  • Security on Hybrid Encryption with the Tag-KEM/DEM Framework
    Toshihide Matsuda, Ryo Nishimaki, Akira Numayama, Keisuke Tanaka
    ACISP 2009 (LNCS 5594)
    acceptance rate = unknown

2006

  • Universally Composable Identity-Based Encryption Ryo Nishimaki, Yoshifumi Manabe, Tatsuaki Okamoto
    VIETCRYPT 2006 (LNCS 4341)
    acceptance rate = unknown

Journal Articles


  • Watermarking Cryptographic Capabilities
    Aloni Cohen, Justin Holmgren, Ryo Nishimaki, Vinod Vaikuntanathan, Daniel Wichs
    SIAM Journal on Computing (to appear)

  • How to Watermark Cryptographic Functions by Bilinear Maps
    Ryo Nishimaki
    IEICE Transactions E102-A(1) (to appear)

  • 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

  • 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

  • Post-Challenge Leakage Resilient Public-Key Cryptosystem in Split State Model
    Eiichiro Fujisaki, Akinori Kawachi, Ryo Nishimaki, Keisuke Tanaka, Kenji Yasunaga
    IEICE Transactions E98-A(3)

  • Key-Private Proxy Re-Encryption from Lattices, Revisited
    Ryo Nishimaki, Keita Xagawa
    IEICE Transactions E98-A(1)

  • An Efficient Non-interactive Universally Composable String-Commitment Scheme
    Ryo Nishimaki, Eiichiro Fujisaki, Keisuke Tanaka
    IEICE Transactions E95-A(1)

  • A Multi-Trapdoor Commitment Scheme from the RSA Assumption
    Ryo Nishimaki, Eiichiro Fujisaki, Keisuke Tanaka
    IEICE Transactions E95-A(1)

  • Universally Composable Identity-Based Encryption
    Ryo Nishimaki, Yoshifumi Manabe, Tatsuaki Okamoto
    IEICE Transactions E91-A(1)

Invited Papers


  • Watermarking Cryptographic Programs (Survey paper)
    Ryo Nishimaki
    Mycrypt 2016 (LNCS 10311) » proceedings ver

PhD Thesis


Constructions for Commitment with Non-Malleability and Universal Composability
Supervised by Keisuke Tanaka at Tokyo Institute of Technilogy

Unpublished manuscript


  • Watermarking Cryptographic Programs Against Arbitrary Removal Strategies
    Ryo Nishimaki, Daniel Wichs
    ePrint Archive » eprint ver
    Most of the results in this paper are superseded by STOC:CHN+16

Books


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