Delft University of Technology: Untappable communication becomes practical with new system in future quantum internet

Engineers from QuTech (a collaboration between TU Delft and TNO) can provide untappable communication that is cost-scaling to many users by using measurement-device independent (MDI) quantum key distribution (QKD).

A notable side-feature is that, courtesy of Cisco, conventional internet operaltes in parallel, on the same optical fibre from Dutch telecom provider KPN. MDI-QKD is an important step towards an accessible quantum internet.

Presently secure communication is based on the fact that breaking cryptography is slow using conventional computers. This includes communication between datacentres, inter-governmental communication, or critical infrastructure like banking, energy and airports. Some communication lines require secrecy by law or by the user. Any attacker could be recording these messages and then decrypting them later. Unfortunately, computers are becoming faster, even more so with the impending introduction of quantum computers.

Ultimate defence against eavesdropping

Joshua Slater, team lead of the MDI-QKD project: 'Important conventional cryptographic methods rely on, for example, a public and a private key. These two keys are essentially two large numbers that belong together. Their security is based on the fact that the private key is difficult and slow to calculate with knowledge of only the public key. Unfortunately, with the introduction of very powerful computers (such as quantum computers), calculating the private key becomes trivially easy and then encryption can become insecure'

Presently secure communication is based on the fact that breaking cryptography is slow using conventional computers. This includes communication between datacentres, inter-governmental communication, or critical infrastructure like banking, energy and airports. Some communication lines require secrecy by law or by the user. Any attacker could be recording these messages and then decrypting them later. Unfortunately, computers are becoming faster, even more so with the impending introduction of quantum computers.

Ultimate defence against eavesdropping

Joshua Slater, team lead of the MDI-QKD project: 'Important conventional cryptographic methods rely on, for example, a public and a private key. These two keys are essentially two large numbers that belong together. Their security is based on the fact that the private key is difficult and slow to calculate with knowledge of only the public key. Unfortunately, with the introduction of very powerful computers (such as quantum computers), calculating the private key becomes trivially easy and then encryption can become insecure'

'A significant achievement that we're demonstrating here for the first time, is that our quantum signals are transmitted over the same fibre as conventional internet traffic,' said Slater. 'Using standard equipment that Cisco supplied and configured with us, we established two multiplexed internet networks between the locations over the same optical fibres. The existence of these two networks do not impact the performance of our quantum system. Essentially, we've shown how our systems can coexist, in parallel'

'This is an important development in guaranteeing the security of internet traffic in the future,' said Babak Fouladi, Chief Digital and Technology Officer and member of the Executive Board at KPN. 'I am pleased that we can contribute towards making this insight practical using the network of the Netherlands. Solutions like MDI-QKD should not only protect users today, but also make communication as future-proof as possible.'

Demonstration in Delft-Rijswijk-The Hague

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: users like Alice and Bob can upgrade their functionality (with e.g. quantum processors, quantum repeaters, quantum entanglement, quantum memory, quantum computers, whatever), while the central node and the rest of the network remains the same. The network is future-proof and ready to be upgraded for the quantum 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 EUR615 million from the Dutch government in April of this year.

More information

Partners

QuTech - Mission-driven research institute for quantum computing and quantum internet and a collaboration between the TU Delft and TNO

KPN - Largest Dutch telecommunications company and provider of the fibre infrastructure that makes this demonstration possible

Cisco - International leader in IT & networking and provider of the telecommunications equipment that establishes the conventional internet running in parallel with the quantum system

Quantum Delta NL - Netherlands' national ecosystem for excellence in quantum innovation

Contact

Joshua Slater, project team lead ([e-mail], [phone])

Aldo Brinkman, press officer QuTech ([e-mail], [phone])

Gerd De Smyter, spokesperson KPN ([e-mail], [phone])

Animation

Watch the animation about the advantages of MDI-QKD.

Credits

Animation: Vincent de Mees, Slim Plot.

https://www.tudelft.nl/en/2021/tu-delft/untappable-communication-becomes-practical-with-new-system-in-future-quantum-internet

(C) 2021 Electronic News Publishing, source ENP Newswire