Quantum Internet

Quantum Applications, Quantum International Relations, Quantum Internet

The quantum internet should be space-based—or should it?


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Feature image via Vice

Satellites have become critical tools in infrastructure and defence. They control GPS systems, enable international communications, allow us to watch the news “live” and track and relay information about the weather and other natural events. They facilitate business and financial communications, as well as radio and telephone capabilities. Satellites have become utterly vital to state infrastructures, making them fundamental assets for competing global powers. Now, we learn that new satellite constellations are being presented as the best way forward to empower a global quantum internet. As the use-value of satellites broadens and we become ever-more dependent on the networks and systems they support, two critical threats loom large. One, the physical threat of space debris; and two, the threat posed by the increasing militarization of space. These challenges to the implementation of a space-based quantum internet have not yet surfaced in the developing debate but must be addressed as we stand on the brink of the quantum age.

New research conducted by a Louisiana State University team led by Sumeet Khatri suggests that satellite-based technology is the best way forward to build a global quantum internet. According to the researchers, a quantum-enabled satellite constellation would be the most cost-effective approach to realise the next big application in quantum communications. Khatri’s team suggests that the most effective and logistically coherent system for a space-based quantum internet would require a constellation of at least 400 satellites, circling the globe in mid-Earth orbit, at an altitude of around 3,000 kilometres. On its own, 400 may not seem like a huge number of satellites, however, by way of comparison, GPS only needs 24 satellites to operate effectively. The nature of quantum entanglement—the essential property of non-locality utilized in quantum-satellite communications—is incredibly fragile, thus requiring a relatively high number of satellites and base stations to allow quantum information to travel without loss of signal.

Space Debris

Currently, there are around 2,000 active and 3,000 non-operational satellites orbiting Earth. Aside from these, National Geographic reports that there could be up to 500,000 pieces of what is known as space debris—man-made bits and pieces separated from rockets, space stations and satellites or simply left behind in space—littering Earth’s orbit. Space debris can vary in size, from a fleck of paint to an entire defunct satellite. It does not float idly through space, but rather, travels at a speed of about 17,500 miles per hour (approximately 28,163 km/h). At such great speeds, even a piece of debris as small as a pebble could cause serious damage in a collision with other Earth-orbiting objects such as space stations or satellites. As such, these collisions not only pose a risk to astronauts and space stations (powerfully depicted in the 2013 film, Gravity) but also to critical satellite-based communications infrastructures.

The challenge posed by space debris has not only made its way in popular culture but is heavily monitored by NASA, as a satellite and space-mission security issue. Today, NASA and the U.S. Department of Defence use ground-based telescopes and laser radars to monitor and report on the locations of more than 1,700 pieces of space debris in order to help prevent collisions with operating spacecraft and satellites. These efforts have so far proven sufficient—only a few collisions have occurred that have caused considerable damage to either spacecraft or satellites, but the potentiality for collision events is becoming increasingly common. At the same time, plans to launch more and more satellites are announced regularly by both state and non-state actors. While the situation is currently manageable, a predicted influx of over 50,000 satellites in orbit over the next decade would certainly tip the scales. A satellite-based quantum internet would, of course, add to this crowded milieu.

As a now poignant 1998 article, The Danger of Space Junk, for The Atlantic warned: “over time everything in Earth’s orbit will be ground into celestial scrap”, creating “a mausoleum of space technology”. Scientists now warn that if we do not manage existing space debris and ensure that future satellites and spacecraft are fitted with de-orbiting mechanisms, this reality will soon come to fruition. Most space-bound objects have no built-in function for de-orbiting and will continue to float (or rather, zoom) through the congested low- and mid-Earth orbit as they break into smaller and smaller fractions through degradation or collision with other orbiting objects. Each collision, no matter how small, exponentially compounds the problem.

This problem, which we are now beginning to witness, is known as the Kessler Syndrome. The eponymous Kessler Syndrome was posed by NASA’s Donald Kessler in 1978 in a co-authored quantitative study on the issue. The theory argues that the continued launching of satellites without a plan for de-orbit will lead to exponential collision frequency, creating a “debris belt” in low-Earth orbit that could render future space exploration and the use of satellites impossibly risky, creating a huge setback that could last generations. This leads to a concerning prognosis for the maintenance of entire space-borne infrastructures, which, among other critical functions, transmit national secrets and protect society from incoming natural and man-made disasters like hurricanes and missiles.

There are a variety of niche innovations underway that aim to confront this encroaching challenge, including Japan’s giant space whip (known as the electrodynamic tether, or EDT), which intends to swat debris out of earth’s orbit, causing it to incinerate as it falls toward Earth. The most effective technology for the job, however, is for future satellites to be built with a functionality to end their own lives once their tasks are complete, using their last bit of power to head back toward Earth where they will burn up in the atmosphere in order to self-decommission. This is currently a rapidly evolving space where new innovations are being applied and tested regularly. Projects like D-Orbit’s purpose-built, de-commissioning cubesat and the World Economic Forum’s 2019 project to create a space sustainability rating look hopeful. These types of conscious industry advances are necessary in order to ensure we avoid the Kessler Syndrome, so we can continue to use space sustainably to host novel satellite applications like a quantum internet.

Security

As we have reported on previously, space itself is no sanctuary from geopolitical rivalries. The implementation of a space-based global quantum internet will present a challenge for the grey area of international space development. Quantum satellites straddle the fine line between non-militarised and militarised infrastructure. Quantum technologies are heavily invested in by military-state apparatus—especially in China and the U.S. For either of these countries, the large-scale deployment of quantum-satellites could push us over that line and into an uncertain future of a highly militarised outer space. Already, U.S. President Donald Trump has initiated the development of a dedicated space arm in the U.S. defence forces with Space Force. In China too, the space and military programs are the same entity. Satellites are the centrepieces in both U.S. and Chinese space-security programs, both in offensive and defensive capacities. Recently, Russia, France and Norway have also invested heavily in satellites for a variety of security motivations.

While the conversation around space-military fusions sounds like the stuff of futurist, sci-fi fiction, it is very much a real and unfolding topic in the meta-geopolitical debate. Meta-geopolitics, untethered from traditional geographic constraints, refers to a new phase of international relations contextualised by the rise of border-defying security threats, like terrorism, cyber warfare and espionage, and global warming. It also extends to outer space, where our ever-growing dependence on satellite-based infrastructure is at increasing risk of interference and jamming by state or non-state actors.

China has been a demonstrated leader in both satellite-based quantum communications and offensive security since 2007, when the country tested its anti-satellite missile—a move that thrust satellites to the top of military agendas, especially in the U.S. In 2016, China launched Micius, the first quantum satellite that would soon facilitate ground-to-space quantum-secure communications across the globe. Since then, as we heard at last year’s Q Symposium from Jingyun Fan of China’s University of Science and Technology (watch his presentation here, from 1:10), China has been hard at work, refining the quantum communications capabilities of Micius. Aside from China and Europe, satellite-enabled quantum communications efforts are also underway in North America and the Indo-Pacific, including in Australia. The development of this new wave of satellite technology is only just beginning in earnest and promises to see more and more purpose-built quantum-satellites launched into earth’s low and middle-orbit in the coming years.

From a security perspective, achieving global quantum communications has long been a target, as it promises to enable hack-proof security for long-distance information transmission. While the achievements have so far been narrow, a space-based quantum internet is the next step in ensuring the tamper-proof transmission of vital information across the globe. It is easy to understand the benefit of these capabilities to any national or allied security apparatus. It is equally clear to see how the targeted destruction of quantum-satellites could become an immensely effective tactic in war. Enter space as a new “operational domain” of war, as recently declared by NATO in November of 2019. The inclusion of space as an operational domain acknowledges both the alliance’s critical reliance on satellite infrastructure and the growing threat posed by anti-satellite weaponry capabilities.

We are witnessing a rapid cluttering and securitization of outer space, a “frontier” that once seemed boundless, beyond human reach. Before state and non-state actors continue to dive head-long into this process, they should pause to consider the reality we are facing—a global, quantum space-based effort would put new pressure on an already saturated and precarious potential field of combat. Maintenance of the status quo will push the world into a grey area in both quantum and political science, where the path forward presents risks we are only just beginning to witness and understand. As our satellite capabilities expand and our tethered dependency on these orbital-objects grows, so too does the severity of the threat of their potential interference, blocking or destruction—by accident or by design.

Project Q, Quantum Applications, Quantum Internet

Project Q Interview: Stephanie Wehner on Building a Quantum Internet


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Feature image via Quanta Magazine

Stephanie Wehner has an impressive resume, to say the least. The German physicist and computer scientist is currently leading Europe’s Quantum Internet Alliance on its mission to build a quantum internet. She is the Roadmap Leader of Quantum Internet and Networked Computing at QuTech, a research centre for quantum computing and the quantum internet at Delft University of Technology in the Netherlands, Co-Founder of QCRYPT (the largest annual international conference on quantum cryptography), and Coordinator for the Quantum Internet Alliance of the EU Flagship, as well as an Antoni van Leeuwenhoek Professor at QuTech, Delft University of Technology. And that is not even mentioning her previous accomplishments and accolades.

We recently sat down with Stephanie to discuss the project’s advancements, future use-values for a quantum internet and the challenging ethics of building a network that will enable un-hackable communications.

The following interview has been edited for clarity.

 

Why are you building a quantum internet?

We are working on building a quantum internet because you can do things with a quantum internet that you cannot do on the internet that you have today.

Of course, the most famous application of quantum communication is secure communications. That’s proof that you can have security that even a quantum computer can never break. But that’s not the only reason why we do it. There are a few other cool things you can do with a quantum internet. For example, if you can imagine that in some years we actually do have quantum computers, then people think the first application of such a quantum computer could be to simulate, say, a new material design. But maybe we will only have this technology here at QuTech and a few other places. One way for you to use such a quantum computer would be to send your material design to us, then we would do the simulation for you and then tell you what the result is. But maybe you don’t want to tell us your material design, given that it might be proprietary. And so the question is, can you perform such simulations and can you use the remote quantum computer in such a way that you don’t have to give away your proprietary design or any other secrets that you want to involve in this computation? And the quantum internet makes it possible to use a very simple quantum device, a quantum terminal, to access a remote quantum computer in such a way that this quantum computer cannot learn what you’re doing. So, it cannot learn what your proprietary material design is, it cannot even learn if you’re doing a simulation or factoring a number—it cannot tell the difference.

There are a few other nice applications. For example, one can synchronize clocks more accurately. One can keep data more efficiently in sync in the cloud. That’s maybe something that is not so obvious to you actually as a user, but you would certainly know if it goes wrong.

Let’s imagine an extreme example: let’s say that you have a million euros in the bank. And the data is, of course, stored somewhere. So, somewhere there’s a database that says that you own that one million euros. So, you can imagine that if you went to the A.T.M. to withdraw money, maybe the system crashes when you withdraw. And usually for redundancy purposes, of course, the data does not exist only in one location because, you know, if the computer burns down, then no one remembers who owns any money. It’s replicated in a few locations. But it might happen that if you don’t employ such consistency protocols, that if your system crashes during withdrawal, then computer one now says you own one million euros and computer two now says you own zero euros. So now the question is, who is correct? So, it’s a very important problem actually to keep data consistent in the cloud so that you don’t run into these kinds of issues.

I understand that one of the most important aspects of a quantum internet is that it will enable ultra-secure communications, which is obviously a huge benefit for state-actors, banks and big corporations. But what are some impacts a quantum internet might have on broader civil society?

I think keeping data consistent, for example, is not something totally big business. I think it’s very difficult to predict the future. The internet that we have today was originally meant to share some files around. And that’s great, but then you might also ask why would I, at home, ever share a file? At that point, in fact, people didn’t even have a personal computer at home, so, what are these files that you’re talking about?

So, we cannot predict all the applications that a quantum internet will have. People have used it also, for example, to cheat an online bridge game with entanglement. Which, of course, is a bit obscure but it may hint that there are many more things one can do with it. But I think if people don’t have access to it, then this will also not come.

A lot of the applications that we run on the internet today were not developed by people somewhere in the 60s where they wrote on the whiteboard and said, “these are all the applications, and now we’re going to build this thing”. But rather, there were people who were engaged with their technology and played around and wanted a social forum and to see whether it could be possible.

To begin with, I know the quantum internet you’re building will have a very limited scope but do you envision this being something that will be accessible to everyone in the future?

I certainly hope so, absolutely. I think the question is just a little bit, when? So, we’re building a small demonstration network here in the Netherlands, where we also have an effort to make it accessible for people. But that will only happen in two or three years because it’s very difficult to have something stable enough that you can begin to do that.

We also already have a quantum internet simulator. It’s a little program that you can install on your computer and you can have something like a pretend quantum internet. And we are using it, actually for a Hackathon next week, together with RIPE NCC (RIPE is the regional internet registry in Europe), and this time it’s actually a pan-European version. So, there will be a few teams across Europe—one here, one at CERN, one in Dublin and a few other places across Europe. And they’re going to basically work together on our “pretend quantum internet” to explore a few things one can do with it.

Given the lessons that we’ve learned from the development of the classical Internet, what sort of legal or ethical challenges do you think future frameworks and regulations for a quantum internet might consider? And are these unique from the challenges that are posed by the classical internet?

To be honest, I think there are other people who are more capable of answering this question. I’m a researcher, I’m not a lawyer and I’m also not a specialist in ethics. Given this position, I can give you a few issues, even though maybe I am partially critical about them myself.

On the one hand, there’s a lot of discussion about standardising various technologies. Which, of course, is very important eventually. On the other hand, I’m also a little bit critical about this because if you start to write standards too early, you constrain the development. Another aspect is the impact of having fundamentally un-tappable communication. That is a question that is maybe not even totally unique to quantum networks. Of course, only quantum networks can deliver fundamentally un-tappable communication, but it also arises to a lesser extent with existing encryption technologies that people might be using.

So, is that a good thing or a bad thing? On the one hand, it’s a very good thing because one can protect government secrets and everyone’s secrets with absolute security. But of course, security always has two sides. If you have a mechanism to make something more secure, it can in principle be used by anyone. It can be used for good, but it can also be used for bad. So that is a little bit of a trade-off between these two things.

I am personally of the opinion that you cannot stop progress. So, you can say, “I’m going to forbid this.” But then people will do it anyway. It’s not possible to forbid technology.

The reason I think a lot of us maybe have some mixed feelings about this is the sense that it’s already super hard to realise that technology. It’s already so hard! So, putting some extra barriers is a very scary thing, right?

There’s been a lot of talk recently about Google’s claim to have achieved quantum supremacy, as you know. But, of course, the reality is that for the most part, quantum computers will work in concert with classical computers, not replace them. In what ways will the quantum internet interact with or rely on existing “classical” technologies?

So, maybe to talk about the term quantum supremacy? In quantum communication, quantum supremacy has been achieved many years ago. Because any QKD implementation basically shows quantum supremacy. So, a quantum internet is not supposed to replace the classical internet but rather, supplement it with some extra functionality that you otherwise don’t have. Because, if you say I’m watching a movie on Netflix, there’s no reason why we would send it via qubits. Maybe in the far future when everything is so far advanced, we could need to do everything in one system. But in my lifetime, I don’t expect this. In all known application protocols for quantum, with a secure communication or say secure quantum computing in the cloud or everything else, you need the quantum network, but you also need to send some classical data around.

So, do the networks overlap or do they sit separately?

That’s a good architecture question. Do they follow sort of the same pattern? They don’t need to follow the same pattern on application level, not at all. On the elementary level—on the control level—whenever you have two quantum nodes that wants to make quantum entanglement, for example, they also need to be able to talk to each other classically, to synchronize.

And is this done using hardware or software?

It’s done through hardware and software, actually, on what is called the physical layer. So next to a quantum channel you always have a classical control channel but it is not visible for the user. But this sort of user-level communication classically could be done also by the standard internet and next to the quantum topology.

What kind of support has this project received on a local, national and regional level as well as privately?

We have a lot of support from the from the Netherlands, actually, both through QuTech, which is a national Icon program from the Ministry of Economic Affairs in the Netherlands and also NWO, which is like the Dutch NSF of the U.S. We also have some amount of research funding from the EU, both from the European Research Council and to a lesser extent from the quantum flagship, which is the EU initiative. We are also the coordinator of the European Quantum Internet Alliance where we work together with some other nodes in Europe.

We also have various industry engagements, for example, we work together with KPN, which is the Dutch Telecom. We also talk to a lot of parties in the classical domain. For example, The Hague Security Delta, which is sort of an umbrella organisation of 80 security companies in the Netherlands. That’s very convenient for us because we don’t have to talk to each of them individually. So that’s very valuable for us. We also talk to a few other private entities in the Netherlands. We also have relations with industry partners on the component level, for example, with Toptica who makes laser systems. Then there’s OPNT that does timing control, JPE that does stabilisation. So, this is on the component level where we work with a lot of industries to do specific things for our quantum network. We also work with industry which is more interested in the use case if you were to go to the other extreme of the spectrum. For example, with SAP, which is a German software company. With these companies, the interest is more about what you can do with the technology.

Another useful thing to mention is that there is also RIPE NCC, which is the regional internet registry of Europe. And that’s actually pretty cool for us because they’re an organisation that brings together all the large telecom operators and internet providers in Europe. They are responsible for managing the numbers on the internet and there cannot be a computer anywhere in Europe that does not have a number from RIPE. But they also do a lot of community development and education of their members.

I know you set the deadline for end of 2020 to have this completed, how’s your progress tracking now?

So, we will have one link by 2020 but we do not have the four nodes yet. We want to have three in 2021 and maybe all four in 2022.

Have there been any surprise challenges that have created this delay?

Of course, there are some technical challenges which took us longer. And, of course, there were also some mundane challenges. We have also decided we would like to deviate from the four-city plan because we would like to put one node somewhere we can physically access it. Previously, we had said we’re going to put it in Leiden, Amsterdam, Delft, The Hague. But then we were thinking that somewhere in the building in Leiden there could be a node, but that it would be in one of these KPN-style buildings where no one can go in. So, this is why we want to put one of the nodes somewhere where you can actually see it. That might happen either here [in Delft] or in The Hague or in Rotterdam, we haven’t quite decided yet. The idea is that you would really have a terminal where you can see the node, otherwise you just have to believe us, right? We tell you, we promise that the node’s over there!

Quantum Applications, Quantum International Relations, Quantum Internet

The ‘Who, What, Where, When and Why’ of a Quantum Internet


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With all of the recent hype about quantum supremacy, it’s easy to forget that quantum supremacy in communications was demonstrated years ago. One of the most exciting developments on the horizon for quantum communications is a quantum internet, which will securely transmit quantum information. Like most things quantum, the label of “quantum internet” has been slapped on to a quantum technological application, establishing a concept that is easily consumable for the masses, which helps to create the hype that keeps funding for that application flowing. The reality, as is often the case, is much more complex.

In fact, just about the only thing that scientists agree on is that the term “quantum internet” does not have an agreed-upon definition. That is because the technology required to manifest this reality is still in its infancy. Scientists around the world are working hard to change that. Perhaps the most well-known is Stephanie Wehner of Delft University of Technology. In preparation for the release of Project Q’s interview with Wehner on this topic, we reflect on the current stage of global development of a quantum internet.

Since 2004, the security afforded by quantum communications has been proven superior by a method known as quantum key distribution (QKD). QKD is a system employed to produce and distribute a secret key that can then be used to encode classical information. This method has since been employed by a number of actors across both private and public sectors, including banks and national security networks. It does not, however provide a secure link by which quantum information can be transmitted. Enter one important motivation for a quantum internet: to create a network of quantum nodes that enables the secure transfer of quantum information. Of course, there are a diversity of useful applications for such a network and many more still which will develop as the technology matures. One needs only to recall the history of the classical internet, for which the first projected use-value was extremely narrow, to imagine the breadth and depth of applications that will surely follow once the technology is functional.

However, a salient challenge for researchers working on a quantum internet remains. Like the classical internet, a quantum internet requires a physical infrastructure in order to function. There have been a diversity of approaches to this complex problem, from diamonds to crystals and drones to satellites. For the most part, however, the emerging dominant systems rely heavily on land-based fibre-optic cables, with some major differences between them.

In 2016 China launched their quantum satellite, Micius, as part of their Quantum Experiments at Space Scale (QUESS) project. Within a year of the satellite’s launch, major goals paving the way for a quantum internet had been achieved by a multi-disciplinary, multi-institutional team from the Chinese Academy of Sciences, led by Professor Jian-Wei Pan. These ground-to-satellite quantum communication advances included the impressive feat of establishing a quantum-secure communication spanning the longest distance yet between two different points on the globe (Beijing and Vienna) via Micius. Recently, China has also constructed the largest fibre-based quantum communication backbone, known as the Beijing-Shanghai quantum link, which stretches a distance of over 1,200 miles. However, while the link is already in use by some of China’s biggest banks to transfer sensitive data, it is not fully quantum-secure (more on that shortly).

While we have known that quantum communication is theoretically possible for some time, China has been the first country to focus its research apparatus on the challenge, building the first dedicated, large-scale infrastructure for the task. From a security perspective, this is a strategic move on China’s part. The focus on quantum communications is a pre-emptive defence mechanism to combat U.S. advances in the quantum computing space. Regardless of the development of computers, which will be capable of hacking any classical communications, a quantum-secure network will be act as a safeguard against prying eyes and ears. As a result, China continues to be a world leader in this space. However, Europe is hot on its heels and lining up to take the cake for the next big development in quantum communications: creating a functioning quantum internet.

You may have heard of the work being done to build a quantum network in the Netherlands by a team of researchers at the Delft University of Technology. Much like China’s Beijing-Shanghai quantum link, the Delft team is constructing a link between four major cities in the Netherlands, stretching from Delft to Amsterdam.

The main difference between the China quantum link and the one being built by Wehner and her team is that the Chinese infrastructure, while greatly improving upon most current cybersecurity capabilities, is still susceptible to hacking. Theoretically, a genuine quantum link will provide un-hackable connection across large distances. The Chinese system relies on 32 nodes across the link in order to transport quantum information, which is carried in photons, or light particles. Each of these nodes is susceptible to hacking because they serve as points where the information must be decrypted and then re-encrypted before the information continues its journey along the link. The system was constructed in this way because quantum information carried in photons can only travel through about 100 miles of fibre-optic cable before it begins to dim and lose data.

A solution to this problem, which Stephanie and her team have incorporated into their design from the outset, and which the Chinese team is beginning to work with as they improve their own link, is the use of quantum repeaters. This is how they work:

A quantum repeater essentially serves the same purpose as an ordinary relay node, except it works in a slightly different way. A network using quantum repeaters is shaped more like a family tree than a linear chain. In this family tree-shaped game of telephone, the quantum repeater is the parent who distributes identical pairs of quantum keys between two children, therefore doubling the possible distance between users. Moreover, these “parents” can also have their own “parents,” which can then double the key-sharing distance between the children at the bottom for every extra level created atop the family tree. This in effect increases the distance a quantum message can be sent without ever having to decrypt it.

An illustration of the type of quantum network being built by the Delft team.

Alongside their use of quantum repeaters, which provide an infrastructure to teleport the quantum entangled information across the link, the Delft team incorporates the use of quantum memories as an essential element in ensuring the information’s hyper-secure journey. Quantum memories store the entangled information in between the repeaters. They are critical because they enable the network to store the quantum information while the next entangled link is prepared, rather than measuring it and thus potentially destroying it. A system enabled by quantum repeaters and quantum memories eliminates the need to incorporate weak security points in the system where the quantum information is decrypted and then re-encrypted, or potentially destroyed.

Though significant challenges remain for researchers working to build a quantum internet, international efforts become more and sophisticated with each passing day, bringing the world closer to potential quantum network connectivity. While it is being built to supplement certain capabilities of the classical internet, some believe that eventually, the quantum internet will even overtake the classical. Most agree, however, that this will not be a reality even in our lifetime. After all, as Wehner commented in a recent interview with Project Q for our upcoming publication, you don’t really need a quantum internet to watch Netflix.

Tune in next week to read our exclusive interview with Stephanie Wehner, where she updates us on the project’s advancements, answers questions about future use-values for a quantum internet and addresses the challenging ethics of building a network that will enable un-hackable communications.

Quantum Internet, Quantum Research

Quantum Teleportation: Paving the Way for a Quantum Internet


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Last week’s big quantum news centred on two proof of concept studies, both of which claim to have achieved quantum teleportation using a tripartite unit of quantum information called a qutrit, for the first time. While quantum teleportation has been demonstrated previously, it has only been carried out with qubits, which are capable of storing less information than qutrits but thought to be more stable. The novel feat was achieved independently by two teams, one led by Chinese physicist Guang-Can Guo at the University of Science and Technology of China (USTC) and the other, an international collaboration headed by Anton Zeilinger of the Austrian Academy of Sciences and Jian-Wei Pan of USTC. While both teams have reported their results in preprint articles, the article by the Austrian-led team has been accepted for publication in Physical Review Letters.

Competition for credit of this achievement aside, the team’s findings ultimately support each other in substantiating an advancement in quantum teleportation theory: namely, that quantum networks should be capable of carrying far more information with less interference than previously thought. This advancement—like many in the world of quantum—is likely to be found most exciting for physicists, evading the grasp of an applied significance for those of us with less scientific minds. Nevertheless, the notion of quantum teleportation has once again grabbed headlines and imaginations, providing a good opportunity to explore the concept and the applied significance that advancements like this might eventually have on our world.

While it may sound flash, quantum teleportation is an affair less akin to science fiction than one might imagine. On a basic level, quantum teleportation differs from ‘Star Trek teleportation’ because it is used to transmit information rather than macroscale physical objects, like human beings. This is possible because of quantum entanglement, a phenomenon of quantum physics that allows us to look at one particle or group of particles and know things about another, even if those particles are separated by vast distances. Quantum teleportation relies on entanglement to transfer information based on this shared state of being demonstrated by entangled particles. As such, quantum teleportation can be defined as “the instantaneous transfer of a state between particles separated by a long distance”.

Quantum teleportation holds the most obvious promise in the discipline of quantum communication, where its impact in secure communication was established as early as 1997. In 2017, Chinese scientists working with a team in Austria made waves with their announcement that they had achieved transnational quantum teleportation, establishing a quantum-secure connection for a video conference between the Chinese Academy of Sciences in Beijing and the Austrian Academy of Sciences in Vienna, some 7,600 kilometres away from each other. The experiment utilized China’s Micius satellite to transmit information securely using photons. Micius is a highly sensitive photon receiver, capable of detecting the quantum states of single photons fired from the ground. These photons, beamed via Micius, acted as qubits, allowing researchers in both countries to access a shared quantum key and thus enabling them to participate in the quantum-encrypted video call. Critically, should the data have been accessed by a third party, the code would be scrambled, leaving evidence of tampering for researchers at both ends of the connection.

This experiment, facilitated by quantum teleportation, proved two fundamental and impactful theories in quantum physics: that quantum communication can provide a previously unfathomable level of security and that it is capable of doing so on a global scale. Given these capabilities and coupled with the new qutrit proof-of-concept work, the realm of applied possibilities for quantum teleportation is expanding.

Aside from ultra-secure, transcontinental video conferences, one very hyped application for quantum teleportation is in the development of a hyper-fast quantum internet. Due to the entangled state of particles, information is transmitted instantaneously in quantum teleportation—faster than the speed of light. However, the transfer of this information is still required to operate within the current confines of classical communication. As such, even quantum information must travel through ground-based fibre optic cables or via photon-sensitive space-based satellites, like China’s Micius. This infrastructure is both expensive and potentially expansive, posing a formidable challenge for a global roll-out of a quantum internet. Still, these early experiments have laid the groundwork for the development of a quantum-secure Wi-Fi by putting theory to the test and producing promising results.

Currently, a team of researchers at Delft University in the Netherlands is working to build a quantum network, using quantum teleportation as the mode of transport for information between linkage points. The project, which aims to connect four cities in the Netherlands, is scheduled for completion in 2020. In China too, researchers are constructing the backbone for a quantum network to connect Beijing and Shanghai. Aside from the support of private corporations such as banks and other commercial entities, progress on the concept of both localised and international quantum networks has been spurned by pressing anxiety about global levels of cybersecurity

A critical advantage to a future quantum internet is the enhanced security afforded by quantum teleportation—the ability to create an unhackable connection. This could have serious implications for national security and could present a potential solution for many foreign surveillance and interference challenges that countries face today. For example, it is now public knowledge in the U.S. that Russia has the demonstrative ability to directly interfere with most paperless voting systems. While states are currently reticent about making changes to the current U.S. vote-casting system, alternatives are slowly being considered—from regressive paper ballot casting to progressive blockchain applications—in order to safeguard American votes against hacking efforts. Quantum teleportation could offer an interesting alternative in this space as the technology continues to develop.

Though quantum teleportation will not be transporting human beings between planets any time soon, it will play a key role in ushering in an internet revolution. While it remains to be seen exactly how that revolution will play out, it is clear that it will bring an unprecedented level of security and speed to global communications. It is also apparent that the level of interest in the secure and high-speed communications afforded through quantum teleportation is broad and deep, spanning both public and private sectors across the globe. Quantum teleportation has recently seen a number of experimental proofs, pushing the field of quantum communications to the fore of quantum development and promising to deliver a much sought-after security transformation within the decade.

Quantum Internet

The Road to a Quantum Internet


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What will a quantum network look like? How will it integrate with the current internet? Image Credit: Google

Alexander Vipond

A research team at the University of Delft in the Netherlands has laid out a roadmap for a quantum internet. Led by Stephanie Wehner, David Elkouss and Ronald Hanson, the trio have set out what is necessary to establish a quantum internet, how it will interact with the current internet, and where it could take us.

The researchers say a quantum internet is not designed to replace the current internet but complement it by offering various advantages.

These include much more secure remote access to the cloud, stronger security identification methods, secure messaging and more accurate time synchronization across devices. The capabilities of a quantum internet would grow as it develops through six stages (see the graphic below). A quantum internet is also capable of developing in parallel to quantum computers which are only necessary to reach its final stage.

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The proposed levels to a full-fledged quantum internet. Image credit: Elkouss et al in Science, Vol. 362, Issue 6412.

The first stage in the process is to build a fast and reliable small network of nodes that can transmit and receive quantum entangled messages. This requires a physical channel to send the message such as a fiber optic cable, a quantum repeater capable of extending the distance information can be sent, and end nodes to receive the messages.

The Delft group is building such a network between four cities in the Netherlands and hopes to replicate the achievements of the ARPANET (the precursor to the modern internet) by sending the first message between Delft University and Amsterdam in 2020. Countries such as China have also been building first stage quantum networks such as the Beijing-Shanghai quantum link for security purposes.

In a world in which the privacy and security of the internet are rapidly eroding in the face of surveillance capitalism, aggressive state espionage, new technological challenges (such as AI and the Internet of Things) and economic incentivisation for speed over security, could a quantum internet act as a partial cure to such dire strategic trends?

The short answer is yes. By using near faultless quantum encryption there is an opportunity for small networks to regain the confidentiality and integrity of their information. The recent use of internet traffic rerouting and cloud hopping to conduct industrial espionage against Western countries including Australia and the United States could be mitigated by quantum secure remote access protocols and the use of quantum internets.

In the final stage of a quantum internet, the creation of quantum byzantine agreements could also help decentralised networks organise and share information safely even when there is a malicious actor hiding amongst them. This is because the arrangement of the system is resilient enough to accommodate up to a third of the actors in the system being bad whilst simultaneously allowing good actors verify their information and carry out their message.

The long answer is that this is a partial technical solution to two human problems. One, the age-old security problem of states stealing and sponsoring proxies to acquire knowledge from competitors. Using a quantum internet will raise the cost for attackers but it will not deter them as the geo-strategic or business imperatives (or a civil-military fusion of the two) for compromising communications will continue to drive their actions. If the stages of a quantum internet can grant increasingly absolute communications security, as it has been theorised to do, what is of a higher likelihood is that it will simply shift attackers’ attention to the humans on either end of the node.

Two, the new-age problem of structural deficiencies in internet security created by digital business models that require huge amounts of data and whose speed of technology iteration undermines the security of the flow of new technologies and infrastructure that fuel the internet’s expansion. The complexity of this problem cannot be answered by one technology and requires multiple solutions to be sought across government and industry.

In the darkness of the web there stands a path of light. The photons that entangle a quantum message, whilst not a silver bullet to problems of cybersecurity, can provide a much greater level of security than what we have now. The scientific and engineering challenges along the six stages will be difficult to surmount. However, by offering a unified approach across industries with a common plan, the Delft team have brought the possibility of a quantum internet several steps closer to being a new part of the web.

For a more in depth look at the future of a quantum internet, you can view Project Q’s interview with Stephanie Wehner here.