Wavelength division multiplexing enabled quantum key distribution – QUANTUM-WDM

Quantum Key Distribution allows two distant users connected by an optical fiber and implementing a well-defined protocol to agree on a cryptographic key with absolute secrecy, guaranteed by the laws of quantum mechanics. QKD has considerably progressed over the past 20 years and has reached a level of technical maturity sufficient to see the emergence of industrial products that are targeting specific market segments in optical network security.
However, the QKD technologies that have been industrialized up to now, all fall in the generic category of discrete-variable QKD and see their performances (such as the maximum reachable distance) dramatically degraded when deployed on standard optical networks, where QKD signals have to be wavelength-multiplexed with other (non-quantum and intense) optical signals that introduce a lot of additional noise. As a consequence QKD deployment is currently restricted to dark fibers.
The objective of QUANTUM-WDM is to design, test, optimize and deploy a proof of concept able to overcome this severe limitation by demonstrating « WDM-enabled QKD ». We will base our prototype on the technology of continuous variable QKD (CVQKD), for which Telecom ParisTech can capitalize on a solid scientific experience as well as strong collaborations with the inventors of the technology. The impact of the innovation that is pursued is expected to be extremely important for the addressable market of CVQKD.