Joint Research Agreement Signed for Long-Distance Quantum Key Distribution Using Quantum Relay Technology

LQUOM, Inc. (Headquarters: Yokohama, Kanagawa; CEO: Kazuya Niizeki; hereinafter "LQUOM"), a startup based at the Kawasaki Business Incubation Center (KBIC) in the Shin-Kawasaki district, which is operated by a consortium including Tsucrea Co., Ltd. (Headquarters: Chiyoda-ku, Tokyo; CEO: Hideki Suzuki; hereinafter "Tsucrea"), has signed a joint research agreement with Toshiba Corporation (Headquarters: Kawasaki, Kanagawa; President and CEO: Taro Shimada; hereinafter "Toshiba"). The agreement focuses on advancing studies toward extending the distance of Quantum Key Distribution (QKD) as part of building a long-term technical foundation and ecosystem for the realization of the quantum internet. In this joint research, the companies will examine the technical challenges and feasibility of extending the distance of next-generation QKD by combining quantum relay systems—expected to be a foundational technology for future quantum communication networks—with QKD systems.

QKD is attracting attention as a technology that realizes secure encrypted communication that cannot be decrypted even by quantum computers, by utilizing the principles of quantum mechanics. Currently, efforts toward social implementation are active, including demonstrations in fields such as finance, healthcare, energy, and data center communications. However, there are still technical challenges to overcome for further distance extension, speed enhancement, and large-scale networking. Quantum relay is an essential element for realizing long-distance quantum communication, including QKD, as it enables long-distance transmission without damaging quantum states. It is expected to be established as a foundational technology for future quantum networks.

The joint research will be conducted from March 2026 to March 2027. The companies will examine the optimal combination for long-distance QKD from various QKD and quantum relay methods, considering both performance and implementation aspects. Toshiba will primarily focus on examining QKD methods, while LQUOM will focus on quantum relay systems. Both companies aim to utilize the knowledge gained from this joint research in the R&D of quantum communication fields, including QKD and the quantum internet, to realize a safe and secure next-generation information infrastructure.