Exclusive / Quantum networking startup Qunnect adds Cisco as investor in new fundraising round

Today, the best method for secure communications is end-to-end encryption. If one person sends an encrypted message across the internet, it doesn’t matter if the message is intercepted because the message can only be read with an encryption key that today’s computers are unable to crack.

One limitation to that method, though, is that more powerful quantum computers in the future could break through modern forms of encryption. It’s possible to store vast quantities of today’s encrypted data in anticipation of one day being able to decrypt it.

The principles of quantum physics can also be used to prevent eavesdropping entirely. In the quantum world, subatomic particles can enter quantum states of superposition (being in multiple states simultaneously) and entanglement (when two particles become linked, no matter how far apart).

But as soon as particles in a quantum state are observed, they immediately cease to be in a quantum state. Therefore, one way to secure a channel of communication is to send quantum particles across the channel. If those particles are observed by an eavesdropper, such as a hacker, it would be immediately obvious, a kind of invisible tripwire for secret communications.

This method of security, known as “quantum key distribution” or “quantum secure direct communication,” works by sending photons in a quantum state over fiber-optic cables.

One of the challenges is that signals in fiber-optic cables degrade over distance. In traditional communication, those signals can be amplified. Quantum particles, on the other hand, can’t be amplified or duplicated without knocking them out of their fragile quantum state.

Qunnect is workingg on a way around that problem with a method known as quantum repeating. In this method, two photons enter a state of entanglement. One stays put, while the other one travels through a fiber-optic cable. When the traveling photon hits a quantum repeater, it becomes entangled with a new photon and then gets out of the way, allowing the new photon to become entangled with the first photon. That process is called quantum swapping, and it can repeat itself over long distances.

Qunnect has not deployed repeaters, but has successfully tested sending entangled photons over existing fiber in a proof of concept demonstration over existing telecommunications lines in New York and more recently showed it could work over 82 kilometers of commercially deployed Deutsche Telekom fiber in Berlin for 17 days.

With the strategic investment from Cisco, Qunnect hopes to turn proof of concept into real customers.

“Cisco is very forward-leaning in the sense that quantum is going to be the next thing. They understand it’s the next wave behind AI and they want to be prepared for it,” Goddard said.

If Qunnect is successful, secure communications could generate meaningful revenue. But Goddard said the goal is to use that as a jumping-off point to more advanced uses that could enable large scale quantum computing.

Current quantum computers use qubits, or bits made of quantum particles, to do calculations that would take the world’s most powerful supercomputers billions of years to complete.

But today’s quantum computers don’t have nearly enough qubits to do the kind of world-changing calculations, like mapping all known proteins and molecules down to the atomic level, that scientists hope they will be capable of doing.

One way to get there is to network smaller quantum computers together, much like today’s AI datacenters connect racks of GPUs together to form one enormously powerful computer.

To make that happen, Qunnect will need to refine its invention and increase the performance of its technology so that multiple quantum computers could be “entangled” together.

Quantum networking is similar to early radio. We’re learning how to send a new kind of information in the form of electromagnetic radiation.

As our understanding of radio evolved, it didn’t just allow clearer signals or more bandwidth. It allowed new kinds of information to travel over the air, enabling mobile phones and global social networks that changed culture and politics. Today, we are just learning how to send quantum bits over fiber-optic cables. The ability to create completely secure lines of communication with quantum principles is an incredible achievement.

If those advances continue and it becomes possible to network vast clusters of quantum computers, the possible outcomes are so wild.

Predicting what it might enable would be like a radio operator in World War I imagining that one day that same technology would one day lead to Uber and TikTok.

In practical terms, quantum networking still faces hurdles, even with recent breakthroughs. Namely, it’s complicated, slow and expensive, TechTarget writes: “Quantum networking is a futuristic concept, even given the development going on across the globe. A common misconception is that quantum communication is faster than the speed of light. The reality is quantum networking often uses conventional communication methods.”

• Before Qunnect could try to scale its quantum networking idea, it had to build something called quantum memory. This Fast Company article does a good job explaining that step and gives more of the backstory on how the company got from there to here.