Corporate Research & Development Center

Quantum Access Network Technology


Toshiba has developed a new scalable approach to building a secure quantum access network that uses a new technology called quantum cryptography to detect eavesdropping of optical fiber with 100% certainty.

The quantum network uses standard passive optical network (PON) technology to connect multiple users in a tree-based architecture so as to allow the sharing of a single-photon (light particle) detector, one of the most complex components necessary for quantum transmission. We have demonstrated that our world-leading single-photon detector can be shared by up to 64 users(*). Our active stabilization technique provides continuous and stable network operation, allowing, for example, the transfer of approximately two hundred 256-bit secret encryption keys per second per user in an eight-user network. This new approach has shown a path for the first time toward implementing quantum cryptography technology in smart grid, smart city, and other networking applications.

The newly developed quantum access network is essential to make quantum cryptography more practical and cost-effective. In the future, we will further improve the speed and robustness of the quantum access network and develop more compact hardware.

This research is partly supported by the "Research and Development of Secure Photonic Network Technologies" commissioned research project of the National Institute of Information and Communications Technology (NICT), Japan.

Overview of quantum access network

Overview of quantum access network

(*) Fröhlich, B. et al. 2013. “A quantum access network.” Nature 501: 69–72. (as researched by Toshiba)