Content of research

The quantum key distribution technology has passed the proof‐of‐principle phase, and research is now under way with an eye on its practical application. Since this is a technology to realize the ultimate confidential communication, field tests and other researches on it are conducted worldwide. In our laboratory, we are examining both theoretical and implementation-related aspects on quantum key distribution. In the real world, things do not always go according to the theory, and experimental results sometimes differ from those expected in theory. Our goal is to examine these discrepancies and quantitatively guarantee the security of cryptographic keys produced on real devices. To this end, we are conducting research to fill the gap between the theoretical studies and the actual device development. We believe that this research will open the way to measure and evaluate the behaviors of the actual quantum devices, and finally to realize practical quantum systems, which will contribute to future quantum networks.

Potential for social implementation

• ・Highly-secret communication (wiretapping-proof)
• ・Authenticated communication (tampering-proof)
• ・Further information security protocols based on shared random numbers between remote locations.

Appealing points to industry and local governments

Our laboratory conducts fundamental research on quantum cryptography, quantum networks and quantum computers, as well as practical research for developing real-world devices as described here. We are focusing on the development of technologies to harness the quantum properties of light.