Successful Demonstration of Quantum Key Distribution Over DWDM Links 

PacketLight Networks, a provider of DWDM and OTN equipment, and Toshiba Digital Solutions demonstrated quantum key distribution (QKD) over DWDM links.

The demo integrated Toshiba’s QKD technology with PacketLight’s OTN encrypted transport technologies, for the purpose of building "efficient, secure, and scalable quantum-safe communication networks," according to a press release.

The demonstration was led by the National Institute of Information and Communications Technology (NICT) of Japan at the Sapporo Snow Festival and the Okinawa testbeds.

PacketLight and Toshiba teams validated the compatibility of quantum communication systems with optical networking infrastructure through a series of evaluations that delivered QKD alongside a high number of conventional DWDM data signals, and demonstrated quantum secure data transmission with QKD encryption.

The validation was conducted over two types of QKD networks in Japan: a long-haul link in Okinawa and a multiplexed QKD link in Sapporo.

Toshiba’s long-haul QKD system in Okinawa utilized PacketLight’s PL-4000M Muxponder to transmit two 200G wavelengths over a 74-km link with the Quantum channel running over 1550 nm. The link performance was measured using a 100G tester, showing 100% throughput and low latency, in compliance with RFC2544 standard.

Toshiba’s multiplexed QKD system in Sapporo utilized PacketLight’s PL-4000M Muxponder to transmit a 400G wavelength, with the Quantum channel running over 1310 nm.

The companies say they demonstrated that QKD-secured signals "can share the same space as classical data transmissions on the same fiber network, and show how QKD technology can be easily deployed on today’s existing networks without the need for a separate fiber."

Using QKD on existing fiber networks could theoretically provide cost savings and increase deployment speed as it removes the need to use dedicated fiber for QKD transmission.

"We are thrilled that the trial with PacketLight was successful,” said Shinya Murai, Senior Fellow, QKD Business Development Office, Toshiba Digital Solutions Corporation. “Toshiba has been at the forefront of quantum computing technology since 1999. We’ve achieved a series of world firsts in quantum technology deployment, developing quantum-secure and future-proof network communications infrastructures that can protect data from any threat – even those posed by quantum computers. This trial has verified that our technology work when connected to PacketLight's equipment, making it accessible to a broader customer base. We will continue to work together with our partners to provide solutions for quantum safe communications."

"The integration of Toshiba's QKD technology with PacketLight's DWDM/OTN devices paves the way for enhanced secure data transmission," said Koby Reshef, CEO of PacketLight. "We take pride in our involvement in this cooperation and eagerly anticipate the market’s response to the new opportunities it presents."