On Key Substitution Attacks against Aggregate Signatures and Multi-Signatures. - Fujita, Yuuki; Sakai, Yusuke; Yamashita, Kyosuke; Hanaoka, Goichiro (2025)

Signatures with Tight Adaptive Corruptions from Search Assumptions. - Hashimoto, Keitaro; Ogata, Wakaha; Sakai, Yusuke (IACR Cryptol. ePrint Arch., 2025)

Constraints and Evaluations on Signature Transmission Interval for Aggregate Signatures with Interactive Tracing Functionality. - Ishii, Ryu; Yamashita, Kyosuke; Song, Zihao; Sakai, Yusuke; Teruya, Tadanori; Matsuda, Takahiro; Hanaoka, Goichiro; Matsuura, Kanta; Matsumoto, Tsutomu (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2024)

More Efficient Two-Round Multi-Signature Scheme with Provably Secure Parameters for Standardized Elliptic Curves. - Takemure, Kaoru; Sakai, Yusuke; Santoso, Bagus; Hanaoka, Goichiro; Ohta, Kazuo (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2024)

Privacy-Preserving Verifiable CNNs. - Attrapadung, Nuttapong; Hanaoka, Goichiro; Hiromasa, Ryo; Koseki, Yoshihiro; Matsuda, Takahiro; Nishida, Yutaro; Sakai, Yusuke; Schuldt, Jacob C. N.; Yasuda, Satoshi (2024)

Anonymous Reputation Systems with Revocation, Revisited. - Hayashi, Ryuya; Katsumata, Shuichi; Sakai, Yusuke (2024)

Attribute-Based Signatures for Circuits with Optimal Parameter Size from Standard Assumptions. - Hayashi, Ryuya; Sakai, Yusuke; Yamada, Shota (IACR Cryptol. ePrint Arch., 2024)

On Key Substitution Attacks against Aggregate Signatures and Multi-Signatures. - Fujita, Yuuki; Sakai, Yusuke; Yamashita, Kyosuke; Hanaoka, Goichiro (IACR Cryptol. ePrint Arch., 2024)

Fault-Tolerant Aggregate Signature Schemes against Bandwidth Consumption Attack. - Yamashita, Kyosuke; Ishii, Ryu; Sakai, Yusuke; Teruya, Tadanori; Matsuda, Takahiro; Hanaoka, Goichiro; Matsuura, Kanta; Matsumoto, Tsutomu (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2023)

Practical Round-Optimal Blind Signatures in the ROM from Standard Assumptions. - Katsumata, Shuichi; Reichle, Michael; Sakai, Yusuke (2023)

Signature for Objects: Formalizing How to Authenticate Physical Data and More. - Hayashi, Ryuya; Asano, Taiki; Hayata, Junichiro; Matsuda, Takahiro; Yamada, Shota; Katsumata, Shuichi; Sakai, Yusuke; Teruya, Tadanori; Schuldt, Jacob C. N.; Attrapadung, Nuttapong; Hanaoka, Goichiro; Matsuura, Kanta; et al. (2023)

More Efficient Two-Round Multi-Signature Scheme with Provably Secure Parameters. - Takemure, Kaoru; Sakai, Yusuke; Santoso, Bagus; Hanaoka, Goichiro; Ohta, Kazuo (IACR Cryptol. ePrint Arch., 2023)

Practical Round-Optimal Blind Signatures in the ROM from Standard Assumptions. - Katsumata, Shuichi; Reichle, Michael; Sakai, Yusuke (IACR Cryptol. ePrint Arch., 2023)

Aggregate Signature Schemes with Traceability of Devices Dynamically Generating Invalid Signatures. - Ishii, Ryu; Yamashita, Kyosuke; Sakai, Yusuke; Teruya, Tadanori; Matsuda, Takahiro; Hanaoka, Goichiro; Matsuura, Kanta; Matsumoto, Tsutomu (IEICE Trans. Inf. Syst., 2022)

Constraints and Evaluations on Signature Transmission Interval for Aggregate Signatures with Interactive Tracing Functionality. - Ishii, Ryu; Yamashita, Kyosuke; Song, Zihao; Sakai, Yusuke; Teruya, Tadanori; Hanaoka, Goichiro; Matsuura, Kanta; Matsumoto, Tsutomu (2022)

Succinct Attribute-Based Signatures for Bounded-Size Circuits by Combining Algebraic and Arithmetic Proofs. - Sakai, Yusuke (2022)

Equivalence between Non-Malleability against Replayable CCA and Other RCCA-Security Notions. - Hayata, Junichiro; Kitagawa, Fuyuki; Sakai, Yusuke; Hanaoka, Goichiro; Matsuura, Kanta (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2021)

Achieving Pairing-Free Aggregate Signatures using Pre-Communication between Signers. - Takemure, Kaoru; Sakai, Yusuke; Santoso, Bagus; Hanaoka, Goichiro; Ohta, Kazuo (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2021)

Aggregate Signature with Traceability of Devices Dynamically Generating Invalid Signatures. - Ishii, Ryu; Yamashita, Kyosuke; Sakai, Yusuke; Matsuda, Takahiro; Teruya, Tadanori; Hanaoka, Goichiro; Matsuura, Kanta; Matsumoto, Tsutomu (2021)

Fully Anonymous Group Signature with Verifier-Local Revocation. - Kitagawa, Ai; Sakai, Yusuke; Emura, Keita; Hanaoka, Goichiro; Tanaka, Keisuke (IACR Cryptol. ePrint Arch., 2021)

Generic Construction of Adaptively Secure Anonymous Key-Policy Attribute-Based Encryption from Public-Key Searchable Encryption. - Hayata, Junichiro; Ishizaka, Masahito; Sakai, Yusuke; Hanaoka, Goichiro; Matsuura, Kanta (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2020)

A Setup-Free Threshold Encryption Scheme for the Bitcoin Protocol and Its Applications. - Hanaoka, Goichiro; Sakai, Yusuke; Shimizu, Toshiya; Shimoyama, Takeshi; Shin, SeongHan (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2020)

Practical Public-Key Encryption Scheme Tightly Secure in the Random Oracle Model. - Sakai, Yusuke; Hanaoka, Goichiro (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2020)

Verifiable Privacy-Preserving Data Aggregation Protocols. - Yasuda, Satoshi; Koseki, Yoshihiro; Sakai, Yusuke; Kitagawa, Fuyuki; Kawai, Yutaka; Hanaoka, Goichiro (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2020)

Semantic Definition of Anonymity in Identity-Based Encryption and Its Relation to Indistinguishability-Based Definition. - Hanaoka, Goichiro; Komatsu, Misaki; Ohara, Kazuma; Sakai, Yusuke; Yamada, Shota (2020)

Achieving Pairing-Free Aggregate Signatures using Pre-Communication between Signers. - Takemure, Kaoru; Sakai, Yusuke; Santoso, Bagus; Hanaoka, Goichiro; Ohta, Kazuo (2020)

Cryptanalysis of Aggregate Γ-Signature and Practical Countermeasures in Application to Bitcoin. - Hanaoka, Goichiro; Ohta, Kazuo; Sakai, Yusuke; Santoso, Bagus; Takemure, Kaoru; Zhao, Yunlei (IACR Cryptol. ePrint Arch., 2020)

Shortening the Libert-Peters-Yung Revocable Group Signature Scheme by Using the Random Oracle Methodology. - Ohara, Kazuma; Emura, Keita; Hanaoka, Goichiro; Ishida, Ai; Ohta, Kazuo; Sakai, Yusuke (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2019)

Group Signatures with Message-Dependent Opening: Formal Definitions and Constructions. - Emura, Keita; Hanaoka, Goichiro; Kawai, Yutaka; Matsuda, Takahiro; Ohara, Kazuma; Omote, Kazumasa; Sakai, Yusuke (Secur. Commun. Networks, 2019)

Field Extension in Secret-Shared Form and Its Applications to Efficient Secure Computation. - Kikuchi, Ryo; Attrapadung, Nuttapong; Hamada, Koki; Ikarashi, Dai; Ishida, Ai; Matsuda, Takahiro; Sakai, Yusuke; Schuldt, Jacob C. N. (2019)

Recent Advances in Attribute-Based Signatures. - Sakai, Yusuke (2019)

Proper Usage of the Group Signature Scheme in ISO/IEC 20008-2. - Ishida, Ai; Sakai, Yusuke; Emura, Keita; Hanaoka, Goichiro; Tanaka, Keisuke (2019)

Equivalence Between Non-malleability Against Replayable CCA and Other RCCA-Security Notions. - Hayata, Junichiro; Kitagawa, Fuyuki; Sakai, Yusuke; Hanaoka, Goichiro; Matsuura, Kanta (2019)

Proper Usage of the Group Signature Scheme in ISO/IEC 20008-2. - Ishida, Ai; Sakai, Yusuke; Emura, Keita; Hanaoka, Goichiro; Tanaka, Keisuke (IACR Cryptol. ePrint Arch., 2019)

Field Extension in Secret-Shared Form and Its Applications to Efficient Secure Computation. - Kikuchi, Ryo; Attrapadung, Nuttapong; Hamada, Koki; Ikarashi, Dai; Ishida, Ai; Matsuda, Takahiro; Sakai, Yusuke; Schuldt, Jacob C. N. (IACR Cryptol. ePrint Arch., 2019)

Tag-KEM/DEM Framework for Public-Key Encryption with Non-Interactive Opening. - Sakai, Yusuke; Matsuda, Takahiro; Hanaoka, Goichiro (IEICE Trans. Inf. Syst., 2018)

Practical attribute-based signature schemes for circuits from bilinear map. - Sakai, Yusuke; Attrapadung, Nuttapong; Hanaoka, Goichiro (IET Inf. Secur., 2018)

Attribute-Based Signatures for Unbounded Languages from Standard Assumptions. - Sakai, Yusuke; Katsumata, Shuichi; Attrapadung, Nuttapong; Hanaoka, Goichiro (2018)

Efficient Two-level Homomorphic Encryption in Prime-order Bilinear Groups and A Fast Implementation in WebAssembly. - Attrapadung, Nuttapong; Hanaoka, Goichiro; Mitsunari, Shigeo; Sakai, Yusuke; Shimizu, Kana; Teruya, Tadanori (2018)

A Consideration on the Transformation from Deniable Group Signature to Disavowable PKENO. - Ishida, Ai; Sakai, Yusuke; Hanaoka, Goichiro (2018)

A Remark on an Identity-Based Encryption Scheme with Non-interactive Opening. - Sakai, Yusuke; Hanaoka, Goichiro (2018)

Generic Construction of Adaptively Secure Anonymous Key-Policy Attribute-Based Encryption from Public-Key Searchable Encryption. - Hayata, Junichiro; Ishizaka, Masahito; Sakai, Yusuke; Hanaoka, Goichiro; Matsuura, Kanta (2018)

Formal Treatment of Verifiable Privacy-Preserving Data-Aggregation Protocols. - Yasuda, Satoshi; Koseki, Yoshihiro; Sakai, Yusuke; Kitagawa, Fuyuki; Kawai, Yutaka; Hanaoka, Goichiro (2018)

Fully Anonymous Group Signature with Verifier-Local Revocation. - Ishida, Ai; Sakai, Yusuke; Emura, Keita; Hanaoka, Goichiro; Tanaka, Keisuke (2018)

Attribute-Based Signatures for Unbounded Languages from Standard Assumptions. - Sakai, Yusuke; Katsumata, Shuichi; Attrapadung, Nuttapong; Hanaoka, Goichiro (IACR Cryptol. ePrint Arch., 2018)

Group Signature with Deniability: How to Disavow a Signature. - Ishida, Ai; Emura, Keita; Hanaoka, Goichiro; Sakai, Yusuke; Tanaka, Keisuke (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2017)

A privacy-enhanced access log management mechanism in SSO systems from nominative signatures. - Nakagawa, Sanami; Nishide, Takashi; Okamoto, Eiji; Emura, Keita; Hanaoka, Goichiro; Sakai, Yusuke; Kodate, Akihisa (Int. J. Appl. Cryptogr., 2017)

Constructions of dynamic and non-dynamic threshold public-key encryption schemes with decryption consistency. - Sakai, Yusuke; Emura, Keita; Schuldt, Jacob C. N.; Hanaoka, Goichiro; Ohta, Kazuo (Theor. Comput. Sci., 2016)

Group Signature with Deniability: How to Disavow a Signature. - Ishida, Ai; Emura, Keita; Hanaoka, Goichiro; Sakai, Yusuke; Tanaka, Keisuke (2016)

Tag-KEM/DEM framework for public-key encryption with non-interactive opening. - Sakai, Yusuke; Matsuda, Takahiro; Hanaoka, Goichiro (2016)

Simple, Secure, and Efficient Searchable Symmetric Encryption with Multiple Encrypted Indexes. - Hirano, Takato; Hattori, Mitsuhiro; Kawai, Yutaka; Matsuda, Nori; Iwamoto, Mitsugu; Ohta, Kazuo; Sakai, Yusuke; Munaka, Tatsuji (2016)

Attribute-Based Signatures for Circuits from Bilinear Map. - Sakai, Yusuke; Attrapadung, Nuttapong; Hanaoka, Goichiro (2016)

Attribute-Based Signatures for Circuits from Bilinear Map. - Sakai, Yusuke; Attrapadung, Nuttapong; Hanaoka, Goichiro (IACR Cryptol. ePrint Arch., 2016)

Shortening the Libert-Peters-Yung Revocable Group Signature Scheme by Using the Random Oracle Methodology. - Ohara, Kazuma; Emura, Keita; Hanaoka, Goichiro; Ishida, Ai; Ohta, Kazuo; Sakai, Yusuke (IACR Cryptol. ePrint Arch., 2016)

Revocable Group Signature with Constant-Size Revocation List. - Attrapadung, Nuttapong; Emura, Keita; Hanaoka, Goichiro; Sakai, Yusuke (Comput. J., 2015)

Disavowable Public Key Encryption with Non-Interactive Opening. - Ishida, Ai; Emura, Keita; Hanaoka, Goichiro; Sakai, Yusuke; Tanaka, Keisuke (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2015)

Dynamic Threshold Public-Key Encryption with Decryption Consistency from Static Assumptions. - Sakai, Yusuke; Emura, Keita; Schuldt, Jacob C. N.; Hanaoka, Goichiro; Ohta, Kazuo (2015)

Disavowable Public Key Encryption with Non-interactive Opening. - Ishida, Ai; Emura, Keita; Hanaoka, Goichiro; Sakai, Yusuke; Tanaka, Keisuke (2015)

Group Signature with Deniability: How to Disavow a Signature. - Ishida, Ai; Emura, Keita; Hanaoka, Goichiro; Sakai, Yusuke; Tanaka, Keisuke (IACR Cryptol. ePrint Arch., 2015)

Group signature implies public-key encryption with non-interactive opening. - Emura, Keita; Hanaoka, Goichiro; Sakai, Yusuke; Schuldt, Jacob C. N. (Int. J. Inf. Sec., 2014)

A Revocable Group Signature Scheme from Identity-Based Revocation Techniques: Achieving Constant-Size Revocation List. - Attrapadung, Nuttapong; Emura, Keita; Hanaoka, Goichiro; Sakai, Yusuke (2014)

Privacy-preserving smart metering with verifiability for both billing and energy management. - Ohara, Kazuma; Sakai, Yusuke; Yoshida, Fumiaki; Iwamoto, Mitsugu; Ohta, Kazuo (2014)

A Privacy-Enhanced Access Log Management Mechanism in SSO Systems from Nominative Signatures. - Nakagawa, Sanami; Emura, Keita; Hanaoka, Goichiro; Kodate, Akihisa; Nishide, Takashi; Okamoto, Eiji; Sakai, Yusuke (2014)

Ciphertext-Policy Delegatable Hidden Vector Encryption and Its Application. - Hattori, Mitsuhiro; Hirano, Takato; Ito, Takashi; Matsuda, Nori; Mori, Takumi; Sakai, Yusuke; Ohta, Kazuo (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2013)

Methods for Restricting Message Space in Public-Key Encryption. - Sakai, Yusuke; Emura, Keita; Hanaoka, Goichiro; Kawai, Yutaka; Omote, Kazumasa (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2013)

A group signature scheme with unbounded message-dependent opening. - Ohara, Kazuma; Sakai, Yusuke; Emura, Keita; Hanaoka, Goichiro (2013)

Group Signatures with Message-Dependent Opening. - Sakai, Yusuke; Emura, Keita; Hanaoka, Goichiro; Kawai, Yutaka; Matsuda, Takahiro; Omote, Kazumasa (2012)

On the Security of Dynamic Group Signatures: Preventing Signature Hijacking. - Sakai, Yusuke; Schuldt, Jacob C. N.; Emura, Keita; Hanaoka, Goichiro; Ohta, Kazuo (2012)

On the Security of Dynamic Group Signatures: Preventing Signature Hijacking. - Sakai, Yusuke; Schuldt, Jacob C. N.; Emura, Keita; Hanaoka, Goichiro; Ohta, Kazuo (IACR Cryptol. ePrint Arch., 2012)

How to Shorten a Ciphertext of Reproducible Key Encapsulation Mechanisms in the Random Oracle Model. - Sakai, Yusuke; Hanaoka, Goichiro; Kurosawa, Kaoru; Ohta, Kazuo (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2011)

On the (Im)possibility Results for Strong Attack Models for Public Key Cryptsystems. - Kawai, Yutaka; Sakai, Yusuke; Kunihiro, Noboru (J. Internet Serv. Inf. Secur., 2011)

Ciphertext-Policy Delegatable Hidden Vector Encryption and Its Application to Searchable Encryption in Multi-user Setting. - Hattori, Mitsuhiro; Hirano, Takato; Ito, Takashi; Matsuda, Nori; Mori, Takumi; Sakai, Yusuke; Ohta, Kazuo (2011)

Towards Restricting Plaintext Space in Public Key Encryption. - Sakai, Yusuke; Emura, Keita; Hanaoka, Goichiro; Kawai, Yutaka; Omote, Kazumasa (2011)

A Generic Method for Reducing Ciphertext Length of Reproducible KEMs in the RO Model. - Sakai, Yusuke; Hanaoka, Goichiro; Kurosawa, Kaoru; Ohta, Kazuo (2010)

Group Signature Implies PKE with Non-interactive Opening and Threshold PKE. - Emura, Keita; Hanaoka, Goichiro; Sakai, Yusuke (2010)