Europe working on a Quantum Internet Impossible To Hack
The pilot expects to be ready in 2020 and will connect several cities in the Netherlands through a network to share data that is hacker proof. But although the theory makes sense, there are still many challenges ahead and China also goes very fast in the quantum internet race
My train from Paris (France) to Rotterdam (The Netherlands) left with an hour late. When I finally arrived in the Dutch city, I discovered that the train going to Delft ( The Netherlands ) had been suspended for maintenance work on the tracks. So after two long bus trips and a taxi ride, I finally arrived at my destination.
It seemed an appropriate situation, since I was going there to learn a little more about the future of communications. My trip was a reminder that, although the transport of people still has a lot of unforeseen failures, every day, every hour and every minute, huge amounts of data flow smoothly and at high speed , through the fiber optic cables that they connect cities, countries and continents.
But these data networks have a weakness: they can be hacked. Among the secret documents leaked a few years ago by the provider of the National Security Agency of the United States (NSA), Edward Snow-den, there was evidence that Western intelligence agencies had managed to connect to the communication cables to spy on the data that flowed through them.
The research institute I visited in Delft, QuTech , is working on a system that could make such a violation impossible . His idea is to take advantage of quantum mechanics to create a totally secure communications network between Delft and three other cities in the Netherlands by the end of 2020.
The QuTech researchers, led by Stephanie Wehner and Ronald Hanson, still face a series of daunting technical challenges. But if they finally succeed , their project could crystallize into a future quantum internet , in the same way as the Arpanet network created by the US Department of Defense. In the late 1960s, it inspired the creation of the internet as we know it today.
The Internet is vulnerable to the type of cyber attacks that Snow-den uncovered because the data still travels through wires in the form of classical bits, a flow of electrical or optical pulses representing ones and zeros. Any hacker who manages to connect to the cables can read and copy those bits in transit.
The laws of quantum physics allow a particle such as an atom, an electron or a light photon (to transmit through optical cables) to occupy a quantum state that represents a one and a zero simultaneously. That particle is called a quantum bit, or cubit. When we try to observe a cube, its mixed state "collapses" and becomes a one or a zero. This means that, if a hacker accesses a flow of cubits, that intrusion destroys quantum information and leaves a clear signal that it has been tampered with, explains Werner.
Thanks to this feature, the cubits have been used for years to generate cryptographic keys in a process known as quantum key distribution (Q.K.D). The data is sent routinely through a network, while the keys needed to decrypt it are transmitted separately in the quantum state.
China has shown some impressive applications of Q.K.D. Last year, he used a satellite called Mencius to transmit quantum cues from space to two ground stations, one in Beijing (China) and the other in Vienna (Austria). The keys were used to decipher classic data for a secure video conference between the two cities. Any attempt to intercept the communication containing the keys would have destroyed them, making it impossible for spies (or anyone else) to decipher the video conference. China has also built a Q.K.D communications network from Beijing to Shanghai (China) that banks and other companies are using to transmit confidential business data.
However, this model has its limitations. The photons can be absorbed by the atmosphere or by the materials of the cables, which means that normally they can only travel a few tens of kilometers. The Beijing-Shanghai network solves the problem by having 32 so-called "trusted nodes" at various points along the network, similar to repeaters that amplify the signal on a common data cable. In these nodes, the keys are decoded in a classical way and then re-encrypted in a new quantum state for their trip to the next point on the route. But this means that trust nodes really are not so reliable. A hacker could violate your security and copy the classic keys without being detected, as well as the company or government that manages the nodes.
Quantum teleportation
Werner, Hanson and their colleagues at QuTech aim to overcome these limitations to build completely safe quantum internet.
The approach they are using is called quantum teleportation . Although it sounds like science fiction, it is a real method of transmitting data based on a phenomenon known as quantum entanglement
Entanglement consists of creating a pair of cubes (light photons, in this case) that share a single quantum state, so that even if they travel in opposite directions, they retain a quantum connection. Changing the state of a photon instantly alters the state of the other in a predictable way, regardless of the distance between them.
So, quantum teleportation requires first sending a pair of intertwined photons to two people, we will call them Alicia and Roberto. Alicia receives her interlaced photon and lets him interact with a "cubit de memorial" that contains the data she wants to transmit to Roberto. This interaction changes the state of your photon, and therefore also changes the status of Roberto's photon. In effect, this "teleports" data from Alicia's memory cube from Alicia's photon to Roberto's photon . The following illustration shows the process in a little more detail.
Another way of looking at it: the pair of interlaced photons are like the two ends of a single-use virtual data cable . Every time Alicia and Roberto want to send data, they first receive a new cable and, since each of them has one end, only they can use it. That is what protects it from illegal intrusions.
It is something very ambitious. Although Holland is a useful test bench since the distances between its cities are quite small. It is likely that to create larger networks you need "quantum repeaters". Unlike the "trusted nodes" in China's network, which convert quantum information into a classical form and then again into quantum, these repeaters, or step stations with quantum processors, will be necessary to extend the entanglement over thousands. of kilometers so that the networks remain inaccessible to hackers.
Assuming that quantum internet becomes a reality, it will raise important issues. Will it be available to everyone, will it only be available to companies and governments with a lot of money while the rest will continue to depend on the less secure classics? And, will governments begin to insist that they need special access points to quantum networks, just as they do now with backdoors in softwares and smartphones?
