A New Traitor Tracing. - Shigeo Mitsunari; Ryuichi Sakai; Masao Kasahara (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2002)

A Construction of 100 bit Public-Key Cryptosystem and Digital Signature Scheme. - Masao Kasahara; Ryuichi Sakai (IACR Cryptol. ePrint Arch., 2003)

ID based Cryptosystems with Pairing on Elliptic Curve. - Ryuichi Sakai; Masao Kasahara (IACR Cryptol. ePrint Arch., 2003)

A Construction of Public Key Cryptosystem for Realizing Ciphertext of Size 100 Bit and Digital Signature Scheme. - Masao Kasahara; Ryuichi Sakai (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2004)

Meta Ring Signature. - Hiroyuki Okazaki; Ryuichi Sakai; Masao Kasahara (IACR Cryptol. ePrint Arch., 2005)

A Construction of Public-Key Cryptosystem Based on Singular Simultaneous Equations. - Masao Kasahara; Ryuichi Sakai (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2005)

Identity-Based Broadcast Encryption. - Ryuichi Sakai; Jun Furukawa 001 (IACR Cryptol. ePrint Arch., 2007)

A Fuzzy ID-Based Encryption Efficient When Error Rate Is Low. - Jun Furukawa 001; Nuttapong Attrapadung; Ryuichi Sakai; Goichiro Hanaoka (INDOCRYPT, 2008)

Cryptanalysis on 2 Dimensional Subset-sum Public Key Cryptosystem. - Tomohiro Shintani; Ryuichi Sakai (ICIS, 2009)

Security analysis of shifted odd knapsack public key encryption scheme. - Ryuichi Sakai; Yasuyuki Murakami; Masao Kasahara (ISITA, 2012)

New method for factoring two RSA moduli with implicit hint. - Ryuichi Sakai; Masao Kasahara (ISITA, 2014)

Security of Knapsack Cryptosystem Using Subset-Sum Decision Problem against Alternative-Solution Attack. - Yasuyuki Murakami; Ryuichi Sakai (ISITA, 2018)

Equivalent Secret Key Attack against Knapsack PKC based on Subset Sum Decision Problem. - Ryuichi Sakai; Yasuyuki Murakami (ISITA, 2018)

High-Density Knapsack Cryptosystem Using Shifted-Odd and Super-Increasing Sequence. - Minami Sato; Sosuke Minamoto; Ryuichi Sakai; Yasuyuki Murakami (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2024)