Making Cryptographic Primitives Harder. - Shingo Hasegawa; Hiroyuki Hatanaka; Shuji Isobe; Eisuke Koizumi; Hiroki Shizuya (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2008)

Toward Separating the Strong Adaptive Pseudo-freeness from the Strong RSA Assumption. - Masayuki Fukumitsu; Shingo Hasegawa; Shuji Isobe; Eisuke Koizumi; Hiroki Shizuya (ACISP, 2013)

On the Length-Decreasing Self-Reducibility and the Many-One-Like Reducibilities for Partial Multivalued Functions. - Ji-Won Huh; Shuji Isobe; Eisuke Koizumi; Hiroki Shizuya (IEICE Trans. Inf. Syst., 2013)

Password-protected secret-sharing schemes without random oracles. - Shingo Hasegawa; Shuji Isobe; Jun-ya Iwazaki; Eisuke Koizumi; Hiroki Shizuya (ISITA, 2014)

On the Complexity of Computing Discrete Logarithms over Algebraic Tori. - Shuji Isobe; Eisuke Koizumi; Yuji Nishigaki; Hiroki Shizuya (IEICE Trans. Inf. Syst., 2014)

A Strengthened Security Notion for Password-Protected Secret Sharing Schemes. - Shingo Hasegawa; Shuji Isobe; Jun-ya Iwazaki; Eisuke Koizumi; Hiroki Shizuya (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2015)

A construction of attribute-based aggregate signatures. - Shingo Hasegawa; Shuji Isobe; Eisuke Koizumi; Hiroki Shizuya; Ryo Takahashi (ISITA, 2016)

A Method for Constructing an Autonomous Decentralized P2P Storage with High Confidentiality and Reliability. - Masayuki Fukumitsu; Shingo Hasegawa; Shuji Isobe; Jun-ya Iwazaki; Eisuke Koizumi; Masao Sakai (CANDAR, 2017)

Autoreducibility and Completeness for Partial Multivalued Functions. - Shuji Isobe; Eisuke Koizumi (IEICE Trans. Inf. Syst., 2017)

A Construction of Cramer-Shoup Like Encryption Protocols Based on the Anshel-Anshel-Goldfeld Key Exchange Protocol. - Shuji Isobe; Jun-ya Iwazaki; Eisuke Koizumi; Atsushi Suda (CANDAR Workshops, 2018)

On a Relation between Knowledge-of-Exponent Assumptions and the DLog vs. CDH Question. - Firas Kraiem; Shuji Isobe; Eisuke Koizumi; Hiroki Shizuya (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2021)

A construction of encryption protocols over some semidirect products. - Shuji Isobe; Eisuke Koizumi (J. Math. Cryptol., 2023)

Ownership Verification of DNN Models Using White-Box Adversarial Attacks with Specified Probability Manipulation. - Teruki Sano; Minoru Kuribayashi; Masao Sakai; Shuji Ishobe; Eisuke Koizumi (CoRR, 2025)