TU Delft: Measurement-Device Independent System (MDI-QKD) Important Step Towards Future Quantum Internet.

(IndiaEducationDiary) A solution to electronic eavesdropping—now and in the future—is the use of quantum key distribution (QKD). In quantum communication, eavesdropping on a message disturbs transmission of the quantum key. Joshua Slater, team lead of the measurement-device independent (MDI-QKD) system explained, “If the quantum signals are disturbed, the users know not to use the generated key for their secure communication line. Once the quantum key is successfully shared with the intended recipient, the rest of the secure communication benefits from ‘forward secrecy’: the assurance that the key distribution cannot be cracked now or in the future.”
“Current commercially available QKD systems are difficult to scale in a network,” Slater explained. “To solve all these problems, we’ve built a measurement-device independent (MDI) QKD system, in which multiple users can be connected via a central node that operates like a typical telephone switch board operator. Importantly, the central node does not need to be trusted. The entire system is designed such that hacking attacks against the central node cannot break the security of the protocol.”
Researchers at QuTech have already previously performed the first proof-of-principle demonstration of MDI-QKD, the first demonstration over deployed fibres, and the first demonstration using cost-effective, off-the-shelf hardware.”
The current system consists of three standard telco racks, each in a different city in the Netherlands. The first ‘user’ connected to the demo setup is code-named Alice and resides in Delft. The second user, called Bob, sits in a KPN building in The Hague. The central node, Charlie, is located in between. Every user is connected to the centre node by a standard optical fibre. Furthermore, the users and the central node are able to communicate over the normal internet, either directly via the (same) optical fibre, or indirectly via any internet connection.
Finally, the MDI-QKD deployment represents an important step towards a future quantum internet. The network is designed to be upgradable in the future.
“This is a great milestone, and an important foundation for the deployment of a national quantum network infrastructure in the Netherlands. That is one of the main goals of the Netherlands’ National Agenda Quantum Technology, which is being executed by Quantum Delta NL,” said Jesse Robbers, director of Quantum Delta NL—which received €615 million from the Dutch government in April of this year.