Construction of high-rank elliptic curves with a nontrivial torsion point. - Koh-ichi Nagao (Math. Comput., 1997)

Improving Group Law Algorithms for Jacobians of Hyperelliptic Curves. - Koh-ichi Nagao (ANTS, 2000)

Generating Secure Genus Two Hyperelliptic Curves Using Elkies' Point Counting Algorithm. - Naoki Kanayama; Koh-ichi Nagao; Shigenori Uchiyama (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2003)

Improvement of ThéLeriault Algorithm of Index Calculus for Jacobian of Hyperelliptic Curves of Small Genus. - Koh-ichi Nagao (IACR Cryptol. ePrint Arch., 2004)

Analysis of Baby-Step Giant-Step Algorithms for Non-uniform Distributions. - Koh-ichi Nagao; Shigenori Uchiyama; Naoki Kanayama; Kazuto Matsuo (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2004)

A Weil Descent Attack against Elliptic Curve Cryptosystems over Quartic Extension Fields. - Seigo Arita; Kazuto Matsuo; Koh-ichi Nagao; Mahoro Shimura (IEICE Trans. Fundam. Electron. Commun. Comput. Sci., 2006)

Decomposed Attack for the Jacobian of a Hyperelliptic Curve over an Extension Field. - Koh-ichi Nagao (IACR Cryptol. ePrint Arch., 2007)

Decomposition Attack for the Jacobian of a Hyperelliptic Curve over an Extension Field. - Koh-ichi Nagao (ANTS, 2010)

On the complexity of Decomposition Attack. - Koh-ichi Nagao (IACR Cryptol. ePrint Arch., 2010)

Decomposition formula of the Jacobian group of plane curve. - Koh-ichi Nagao (IACR Cryptol. ePrint Arch., 2013)

Equations System coming from Weil descent and subexponential attack for algebraic curve cryptosystem. - Koh-ichi Nagao (IACR Cryptol. ePrint Arch., 2013)

Complexity of ECDLP under the First Fall Degree Assumption. - Koh-ichi Nagao (IACR Cryptol. ePrint Arch., 2015)

Polynomial time reduction from 3SAT to solving low first fall degree multivariable cubic equations system. - Koh-ichi Nagao (IACR Cryptol. ePrint Arch., 2015)

Bit Coincidence Mining Algorithm. - Koh-ichi Nagao (IACR Cryptol. ePrint Arch., 2015)

Bit Coincidence Mining Algorithm II. - Koh-ichi Nagao (IACR Cryptol. ePrint Arch., 2016)

Maximum Number of Steps Taken by Modular Exponentiation and Euclidean Algorithm. - Hiroyuki Okazaki; Koh-ichi Nagao; Yuichi Futa (Formaliz. Math., 2019)