| 2005 | WCNC | Predictive rate control for realtime video streaming with network triggered handover. | Susumu Ishihara, Kenji Koyama, Goh Miyamoto, Masahiro Kuroda |
| 1999 | ASIACRYPT | Modulus Search for Elliptic Curve Cryptosystems. | Kenji Koyama, Yukio Tsuruoka, Noboru Kunihiro |
| 1998 | EuroCrypt | Equivalence of Counting the Number of Points on Elliptic Curve over the Ring Z | Noboru Kunihiro, Kenji Koyama |
| 1995 | EuroCrypt | Fast RSA-type Schemes Based on Singular Cubic Curves y | Kenji Koyama |
| 1992 | CRYPTO | Speeding up Elliptic Cryptosystems by Using a Signed Binary Window Method. | Kenji Koyama, Yukio Tsuruoka |
| 1992 | EuroCrypt | Secure Conference Key Distribution Schemes for Conspiracy Attack. | Kenji Koyama |
| 1991 | ALT | An interactive knowledge transfer model and analysis of "Mastermind" game. | Kenji Koyama, Tony W. Lai |
| 1991 | ALT | A knowledge transfer model: From zero-knowledge to full-knowledge. | Yasuyuki Tsukada, Kenji Koyama |
| 1991 | CRYPTO | New Public-Key Schemes Based on Elliptic Curves over the Ring Z | Kenji Koyama, Ueli M. Maurer, Tatsuaki Okamoto, Scott A. Vanstone |
| 1990 | ASIACRYPT | Direct Demonstration of the Power to Break Public-Key Cryptosystems. | Kenji Koyama |
| 1990 | ASIACRYPT | Meet-in-the-Middle Attack on Digital Signature Schemes. | Kazuo Ohta, Kenji Koyama |
| 1990 | ASIACRYPT | Demonstrating Possession without Revealing Factors and its Application. | Hiroki Shizuya, Kenji Koyama, Toshiya Itoh |
| 1990 | CRYPTO | Nonlinear Parity Circuits and their Cryptographic Applications. | Kenji Koyama, Routo Terada |
| 1990 | EuroCrypt | Membership Authentication for Hierarchical Multigroups Using the Extended Fiat-Shamir Scheme. | Kazuo Ohta, Tatsuaki Okamoto, Kenji Koyama |
| 1988 | EuroCrypt | Security of Improved Identity-Based Conference Key Distribution Systems. | Kenji Koyama, Kazuo Ohta |
| 1987 | CRYPTO | Identity-based Conference Key Distribution Systems. | Kenji Koyama, Kazuo Ohta |