Piece In Hand Concept for Enhancing the Security of Multivariate Type Public Key Cryptosystems: Public Key Without Containing All the Information of Secret Key. - Shigeo Tsujii; Kohtaro Tadaki; Ryou Fujita (IACR Cryptol. ePrint Arch., 2004)

Proposal for Piece In Hand Matrix Ver.2: General Concept for Enhancing Security of Multivariate Public Key Cryptosystems. - Shigeo Tsujii; Kohtaro Tadaki; Ryou Fujita (IACR Cryptol. ePrint Arch., 2006)

Proposal for Piece in Hand Matrix: General Concept for Enhancing Security of Multivariate Public Key Cryptosystems. - Shigeo Tsujii; Kohtaro Tadaki; Ryou Fujita (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2007)

Nonlinear Piece In Hand Perturbation Vector Method for Enhancing Security of Multivariate Public Key Cryptosystems. - Ryou Fujita; Kohtaro Tadaki; Shigeo Tsujii (IACR Cryptol. ePrint Arch., 2008)

Nonlinear Piece In Hand Matrix Method for Enhancing Security of Multivariate Public Key Cryptosystems. - Shigeo Tsujii; Kohtaro Tadaki; Ryou Fujita (IACR Cryptol. ePrint Arch., 2008)

Proposal of PPS Multivariate Public Key Cryptosystems. - Shigeo Tsujii; Kohtaro Tadaki; Masahito Gotaishi; Ryou Fujita; Masao Kasahara (IACR Cryptol. ePrint Arch., 2009)

Security Enhancement of Various MPKCs by 2-Layer Nonlinear Piece in Hand Method. - Shigeo Tsujii; Kohtaro Tadaki; Ryou Fujita; Masahito Gotaishi; Toshinobu Kaneko (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2009)

Proposal of a Signature Scheme based on STS Trapdoor. - Shigeo Tsujii; Masahito Gotaishi; Kohtaro Tadaki; Ryou Fujita (IACR Cryptol. ePrint Arch., 2010)

Dually-Perturbed Matsumoto-Imai Signature (DPMS) Scheme. - Masahito Gotaishi; Kohtaro Tadaki; Ryou Fujita; Shigeo Tsujii (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2010)

Scheme overcoming incompatibility of privacy and utilization of personal data. - Shigeo Tsujii; Kohtaro Tadaki; Ryou Fujita; Hiroshi Yamaguchi; Masahito Gotaishi; Yukiyasu Tsunoo; Takahiko Syouji; Norihisa Doi (ISITA, 2012)

Construction of the Tsujii-Shamir-Kasahara (TSK) Type Multivariate Public Key Cryptosystem, which relies on the Difficulty of Prime Factorization. - Shigeo Tsujii; Kohtaro Tadaki; Masahito Gotaishi; Ryou Fujita (IACR Cryptol. ePrint Arch., 2012)

Privacy Preserving Data Processing with Collaboration of Homomorphic Cryptosystems. - Shigeo Tsujii; Hiroshi Doi; Ryou Fujita; Masahito Gotaishi; Yukiyasu Tsunoo; Takahiko Syouji (Financial Cryptography Workshops, 2013)