| 2026 | ACISP | Threshold FHE with Short Decryption Shares Without a Semi-trusted Server. | Hiroki Okada, Tsuyoshi Takagi |
| 2025 | ASIACRYPT | Low Communication Threshold FHE from Standard (Module-)LWE. | Hiroki Okada, Tsuyoshi Takagi |
| 2025 | EuroCrypt | On Algebraic Homomorphic Encryption and Its Applications to Doubly-Efficient PIR. | Hiroki Okada, Rachel Player, Simon Pohmann, Christian Weinert |
| 2025 | ICISSP | Gram Root Decomposition over the Polynomial Ring: Application to Sphericalization of Discrete Gaussian. | Hiroki Okada, Tsuyoshi Takagi |
| 2025 | IWSEC | Refined Analysis of the Concrete Hardness of the Quasi-Cyclic Syndrome Decoding. | Shintaro Narisada, Hiroki Okada, Yusuke Aikawa, Kazuhide Fukushima |
| 2024 | FC | Towards Practical Doubly-Efficient Private Information Retrieval. | Hiroki Okada, Rachel Player, Simon Pohmann, Christian Weinert |
| 2023 | ACNS | Spherical Gaussian Leftover Hash Lemma via the Rnyi Divergence. | Hiroki Okada, Kazuhide Fukushima, Shinsaku Kiyomoto, Tsuyoshi Takagi |
| 2023 | ASIACRYPT | Homomorphic Polynomial Evaluation Using Galois Structure and Applications to BFV Bootstrapping. | Hiroki Okada, Rachel Player, Simon Pohmann |
| 2023 | ICISSP | Revisiting the DFT Test in the NIST SP 800-22 Randomness Test Suite. | Hiroki Okada, Kazuhide Fukushima |
| 2023 | SECRYPT | SoK: Towards CCA Secure Fully Homomorphic Encryption. | Hiroki Okada, Kazuhide Fukushima |
| 2022 | SECRYPT | Side-channel Analysis and Countermeasure for Implementation of Lattice-based Signature. | Kazuhide Fukushima, Hiroki Okada, Sofiane Takarabt, Amina Korchi, Meziane Hamoud, Khaled Karray, Youssef Souissy, Sylvain Guilley |
| 2021 | SECRYPT | A Comparison of GKE Protocols based on SIDH. | Hiroki Okada, Shinsaku Kiyomoto, Carlos Cid |
| 2020 | ICICS | A Compact Digital Signature Scheme Based on the Module-LWR Problem. | Hiroki Okada, Atsushi Takayasu, Kazuhide Fukushima, Shinsaku Kiyomoto, Tsuyoshi Takagi |
| 2019 | ICNC | Automatic Segmentation of Visible Epicardium Using Deep Learning in CT Image. | Ziyu Zhao, Yutaro Iwmoto, Yuji Tezuka, Hiroki Okada, Kiyosumi Maeda, Atsuyuki Wada, Atsunori Kashiwagi, Yen-Wei Chen |
| 2018 | ICISC | On the Complexity of the LWR-Solving BKW Algorithm. | Hiroki Okada, Atsushi Takayasu, Kazuhide Fukushima, Shinsaku Kiyomoto, Tsuyoshi Takagi |
| 2018 | WISTP | Linear Depth Integer-Wise Homomorphic Division. | Hiroki Okada, Carlos Cid, Seira Hidano, Shinsaku Kiyomoto |
| 2005 | IGARSS | Accuracy improvement of ESPRIT-based polarimetric SAR interferometry for forest height estimation. | Hiroyoshi Yamada, Hiroki Okada, Yoshio Yamaguchi |