The Internet has been a true revolution our own life-time (certainly mine since I first started getting online in the mid 90’s). Now as new technologies such as Quantum are starting to gain traction, could we see a Quantum Internet, i.e. an Internet that uses Quantum Physics at the core as a protocol. We explore what the Quantum Internet actually means and how it could impact on the future of almost everyone.
Before the web, was the internet and before that was the ARPANET, a military project that was designed during the cold war to ensure continuing function of the allied powers. ARPANET, the pre-cursor of the Internet on October 29, 1969 sent its first message. We now take rich interconnection for granted with social media, streaming video and the ability to use tools such as zoom, Facebook and Skype to communicate globally.
Quantum? Isn’t that just a buzz term?
You might be forgiven that Quantum is just a buzz term applied to make products and out of date technology sound smarter and bette. Quantum is something fundamentally very different about the way that we think about information and matter. Normally we think of bits and bytes as constituting the make-up of the information world, the letters and numbers on the screen, the data on your hard-drive, are all encoded into binary digits or bits. However the Quantum world in the sense in which we explore here is very different, and the unit of store or information is a Quantum bit or Qubit for short.
As you may have heard Quantum can be quite difficult to interpret unlike the classical bit – which only has two states. That means thinking about information and data in a very different way. But researchers would not be interested in building a Quantum Internet unless there was some kind of benefit to using quantum physics to represent data.
At the core of building a Quantum Internet are applications that use the special nature of Quantum physics to ensure better security. With carefully constructed protocols, security can be “baked-in” due to the nature of the quantum world. Researchers in Quantum communications can do some pretty special things with Qubits – that is entangle them and put them into superpositions.
Right now, some of the worlds most prestigious labs and well known technology companies are exploring how Quantum computers could open the door to enhanced computing and the ability to compute particular algorithms faster than currently known (classically) algorithms. Much of progress in computing has come from the ability to have ever more powerful and faster computing. Moore’s law can usefully illustrate how processor performance has steadily increased. Conventional fabrication is increasingly difficult and researchers are finding smarter ways to compute, Quantum being one of them.
IBM, Google, Intel, Microsoft and Amazon are all working on some aspect of the Quantum stack (components that can be assembled). Four years ago IBM opened their cloud based Quantum Computing effort named IBM Q.
There are fears that Quantum algorithms namely Shor’s Algorithm, will allow current security protocols to be broken (most of the world runs on these security protocols). The potential solution to some of the security issues thrown open by Quantum Computers could be readily addressed by using Quantum Mechanics itself.
Interconnected Quantum devices
Quantum computers currently have few Qubits and are yet to find their “Killer Application”, however the number of qubits is steadily growing and improving in both number and quality. IBM recently announced their quantum roadmap where they outline the progress to achieve more powerful quantum computers in the coming years.
One aspiration of researchers is to build a network of devices that can communicate with each other, much like we see today with the internet – machines connected with each other using appropriate protocols to relay messages and retrieve information. All of this is happening without much care for the end users. Machines have access to data that might be stored on another machine physically in a Database on the other-side of the planet.
Imagine the potential if quantum computing devices can communicate. Metcalfe’s law states that the usefulness of a network is proportional to the square of the number of nodes. Right now in the Quantum space there is not really any network that we could call useful or powerful.
Then it is no wonder that researchers are keen to get quantum computers connected as much as possible. The goal would be that devices can store, communicate and interact in the full quantum sense.
The aim of quantum networking isn’t just a re-run of classical networks, the principles of quantum mechanics can offer something truly very unique and some very non classical properties – that is entanglement. This spooky behavior is one of the fundamental tenets that researchers are keen to explore. Researchers exploring cryptography can use the principles of entanglement to provide more secure communication protocols.
One of the fundamental principles of entanglement is that particles, or photons (as a type of particle) for example show correlation at a distance. That is that even at large distances apart particles that are entangled exhibit this strange and spooky correlating behavior. By correlation, what we mean is that measuring one particle and then the other, we can see if we measure particle A we can know the state of particle B despite being non-local. The particles of choice in these entanglement scenarios are photons – and whilst entanglement is not limited to just photons, light presents the ability to travel vast distances with ease and speed. We already have much of the technology that enables us to transmit photons – optical fibres which criss-cross the globe enabling us to stream information and movies at high speed.
Some of the early applications of Quantum Communications have been security – especially in the field of QKD or Quantum Key Distribution which aims to solve the problem as the name suggests of transmitting keys without eavesdropping. The QKD protocol enables two parties to produce a shared random secret key known only to those parties, which can then be used to encrypt and decrypt messages. These systems are now commercially and practically viable for some applications.
No cloning theorem. Repeat After Me.
One of the fundamental tenets of Quantum Mechanics is that states cannot be cloned. In the classical sense (the world we we traditionally deal with) it is simple enough to copy the state of a system. The letter ‘C’ in binary, can easily be read and copied. But in the quantum world this is not possible. States if read are destroyed and therefore simple classical elements of our existing network such as repeating stations are not possible in the quantum realm. A device with Qubits cannot readily transmit or copy the state of the Qubits by ordinary means.
China has shown by satellite that it is possible to create communication at distance via entanglement. Launched in 2016, the Micius Quantum Satellite can produce pairs of entangled photons.
Researchers have employed Micius to beam entangled photons to observatories around 1200 kilometers apart in China, allowing those two locations to share quantum encrypted data – further then ever before demonstrated. The ultimate dream is to create a kind of un-hackable network, a quantum internet that pervades the globe allowing secure communications for not only today’s applications but also all kinds of future unknown applications.
In Europe in a lab, a few researchers are also pushing the boundaries to quantum communication at scale. Delft TU has attracted major Quantum research talent and formed an institute dedicated to furtherance of Quantum Computing and the Quantum Internet, QuTech. Among the talent, we must highlight the work of Stephanie Wehner who is the research lead for the Quantum Internet Division. Stephanie is one the founders of QCRYPT, which has become the largest conference in quantum cryptography and is a professional hacker. Certainly she is someone you want building any communication protocol – someone who knows how to break into and hack systems better be on your side.
Companies, governments and organizations are all be looking for ways to build on the secure properties of the Quantum Internet. Scientists are interested in how to facilitate mass communication of Quantum devices. In fact networks might be the way that we achieve radical advances in computation – much like we access the cloud and run computing jobs across multiple processors without much thought – distributing computing across different processors. Specialist chips such as GPU’s and TPU’s exist in the classical data world that give real-time performance gains for modern workflows – accelerating the share price of the companies such as NVIDIA and AMD creating these realities today.
Applications of the Quantum Internet
The following applications are no means exhaustive but are more near term uses of the Quantum Internet. Applications could be almost limitless. One application that we particularly like is Distributed Quantum Computing, but this is likely a much longer term goal.
- Secure Communication. We have all heard of the issues surrounding our current communication protocols. So not a surprise that the Quantum Internet can offer us secure transactions. Whether banking transactions or payment infrastructure or just sending information in a robustly secure manner.
- Secure Networks. Quantum Key Distribution (QKD) might provide the way we can all login and access the systems we want in a secure way, whether this is an ATM, payment service or university exam service or voting for example.
- Secure GPS. Much of the world is relying on GPS or global positioning for so much of the services they provide – from self-driving and navigation and perhaps in the future package delivery by drone. Such systems were not designed to be inherently secure – that calls for more secure protocols to ensure that no hackers can manipulate positional data.
What might the future look like?
We are at the very early stages of the Quantum Internet and whilst entanglement can be demonstrated at large distances, we know how difficult it can be to deal with the issues of fidelity in the classical world without the complexities of Quantum thrown in. There are many aspects that need to be resolved, for example how to repeat signals and how to effectively store quantum states. Concepts such as QRAM (rather akin to RAM) are thought to be able to provide storage of Quantum states, but these are mythical beasts and do not yet exist, practically.
The wider difficulties experienced in the Quantum Computing domain such as storage, encoding, error correction, fidelity are all being addressed but these issues will be overlapping with the same issues in the communication and internet domain.
We humans need to get classical data into and out of the systems, of course to be useful to us, but once encoded, the data can live in the quantum realm and all communications can be done as required in the Quantum space.
Once some of the kinks have been ironed out (and there are some substantial challenges), Quantum networks could grow rapidly and not only replace the classical linkages we take for granted, but allow secure transactions to take place globally. Then there is the network of machines linked together, perhaps to take advantage of Distributed Quantum Computing behind the scenes – machines talking to other machines as the need arises. Just as the cloud computing paradigm can sanction resources to train a neural network, we might see the quantum equivalent, perhaps even training a network using Quantum Machine Leaning.
As we are at the beginning of the Quantum Internet it is hard to speculate where we may be in 10 years time. As few as even just 15 years ago could not imagine the demise of the CD or physical media. Prediction is a difficult business. But if you look at CD/DVD sales you see how steaming has disrupted that industry rapidly and the network has taken on the physical delivery network. It should be no surprise we could see similar levels of disruption with other networks, once there are applications there to make use of. We do have Metcalfe’s law (power and usefulness of networks), meaning that if we can network quantum machines, they’ll likely grow to be very useful indeed…but for exactly what is still to be determined.