暗号・情報セキュリティ研究室西出研究室 | Lab. of Cryptography and Information Security

NISHIDE LAB.

Unauthorized access to computers and information leaks can cause serious damage, so building a safe and trustworthy digital society is more important than ever. Today, information technology is everywhere, and while cryptography and security technologies often work quietly in the background, their role is absolutely essential. In fact, many new businesses and services that use networks are only possible thanks to core technologies like cryptography and authentication.
At Laboratory of Cryptography and Information Security, we focus on research in information security with cryptography at the center. Through our work, we aim to support the development of a society where people can use technology with confidence and peace of mind.

Announcement

2026/03/12News: Our paper, co-authored with Ph.D. student WANG Zhongqi, master's student Haruto Fujita, and Shintaro Narisada of KDDI, Leveraging Tree-Based BSGS and Lazy Relinearization for Efficient Homomorphic Evaluation of Bivariate Functions in BFV, has been accepted for publication in a journal.
2025/10/14News: Our paper, co-authored with master's student Kyosuke Sekii, One-Time Memories Secure against Depth-Bounded Quantum Circuits, has been accepted to Indocrypt, an international conference.
2025/10/01Announcement: Our lab will hold an info session for third-year undergraduates at University of Tsukuba on the following dates.
– 2025/10/22(Wed) 18:15-19:00 @Laboratory of Advanced Research B, Room 812
– 2025/10/23(Thu) 18:15-19:00 @Laboratory of Advanced Research B, Room 812
– 2025/10/27(Mon) 18:15-19:00 @Laboratory of Advanced Research B, Room 701-1
2025/09/25News: Our paper, co-authored with Ph.D. student WANG Zhongqi, master's student Haruto Fujita, and Shintaro Narisada of KDDI, Improving Homomorphic Evaluation of Bivariate Functions in BFV via Tree-Based BSGS with Lazy Relinearization, has been accepted to CANDAR, an international conference.
2025/09/07News: Our paper, co-authored with Ph.D. student XU Ye, Publicly Verifiable Multi-server Homomorphic Secret Sharing, has been accepted to ISPEC, an international conference.
2025/06/10News: Our journal paper, co-authored with Ph.D. student XU Ye, Lattice-based Multi-key Homomorphic Signatures Forward-unforgeable against Signing Key Leakage, has been accepted for publication in a journal.
2025/06/05News: Our paper, co-authored with Ph.D. student XU Ye, VeHSS: Two-server Verifiable Homomorphic Secret Sharing Leveraging SIMD Operations, has been accepted for publication in a journal.
2024/03/01News: 王中琦さんが筑波大学大学院リスク・レジリエンス工学学位プログラムより優秀賞を受賞しました
2024/03/01News: 関井恭介さんが筑波大学情報学群より学群長賞を受賞しました
2024/03/01Annnouncement: 2024年度のリスク・レジリエンス工学学位プログラムのOpen Campusは2024/4/21(日)です。本研究室も研究室公開(対面/online両方)を行います。
2016/02/19Event: 岡本栄司教授退職記念事業のご案内