Research and Development


To establish Secure Photonic Network based on the QKD technology, the basic performance enhancement and stability improvement of the QKD system are necessary. In addition, to enlarge application areas of Secure Photonic Network, an interfacing function for secure keys shared among multiple user terminals should be developed. To this end, we pursue the following two subthemes.

Subtheme 1: Stabilization technique
1a: Develop a stable QKD system against the system instabilities, such as time fluctuations of the photon polarizations in sources and fibers.
1b: The theoretical research on key distillation, such as privacy amplification and error correction, leads to an efficient algorithm. Its result will be applied for enabling fully software-based implementation of efficient key distillation.
Subtheme 2: Enhancing application platform
The aim of this subtheme is to develop new applications of the QKD mobile phones, in which voice data are encrypted by one-time pad (OTP) with secure keys shared by QKD. Extending OTP mobile phone software to Android platform is necessary for wider-applications. They would benefit potential customers such as governmental or financial institutions who demand high-end network security.
Theme concept

Fig. 1Theme concept

Interim results

Interim results for Team 157A-T01

Task title Outcome Date Note
1a: Stabilization of polarization fluctuations Experiments for investigating the impact of the polarization fluctuations in a photon source Jul. 2013 OCS2013
1b: Optimization and implementation of key distillation Improved key rates by improved security analysis (Finite size analysis, hash function) Sep. 2012 New J. Phys. 14, 093014 (2012)
Jun. 2013 IEEE Trans. IT 59, 4700 (2013)
Fully software-based key distillation (EC with HARQ, PA with FFT algorithm) Mar. 2012 ISEC2010
2: One-time-pad mobile phone software Conceptual design Mar. 2013  
Porting software to Android OS Oct. 2013 Prototype
Design common key supply interface Oct. 2013  


Targets for Team 157A-T01

Task title Work/Milestone Due Date Note
2: Optimization and implementation of key distillation Software implementation for DPS-QKD Mar. 2015 Optimization
Software implementation for CVQKD Mar. 2015 Feasibility study
Software implementation for NEC's QKD Mar. 2015 Feasibility study
3: One-time-pad mobile phone software One-time pad mobile phone software on Android Mar. 2016 Demonstration and test in cellular network



Chart 1Schedule for Team 157A-T01

Task 2: implements a downsized, cost reduced and more flexible distiller.

Task 3: contributes to the quantum cryptography application design.