Most of the research in this arena has been focused on theoretical constructs, with the exception of quantum computing. Unlike traditional binary computing, which relies on moving information in the form of zeroes and ones, quantum computing isn’t limited to two states. Instead, quantum computers encode information as quantum bits, or “qubits”, which represent atoms, ions, photons or electrons and their respective control devices, working together to act as computer memory and a processor.

Because the laws of quantum physics allow a particle to occupy a quantum state that represents a combination of 1 and 0 simultaneously, qubits are promising to offer a more secure form of communication. When a qubit is observed by an outside source – that is, a source outside of the official sender or receiver – its state “collapses” to either 1 or 0. This means that if a hacker taps into a stream of qubits, the intruder not only leaves a clear signal that it’s been tampered with, but actually destroys the quantum information in that stream.

This property has been used for a while now to generate encryption keys in a process known as quantum key distribution (QKD). This involves sending data over a network normally, but the keys needed to decrypt the data are transmitted separately in a quantum state.

The success of this form of encryption has resulted in a number of researchers across the globe actively working on creating a more secure version of the Internet, based on quantum entanglement. They are calling the new means of data transfer “quantum teleportation”, and it has successfully been used in a number of laboratory tests. Most recently, a particle known as a qutrit, which is like a qubit but with a third dimension, was teleported across the world, demonstrating that quantum teleportation could form the backbone of worldwide communications following a bit more research and development.

The Austrian Academy of Sciences, the University of Vienna, and the University of Science and Technology of China have all contributed to the body of knowledge being used in these advances, as have a number of private companies and government organisations. At the ICFO Institute of Photonic Sciences in Barcelona, for example, researchers have built a prototype quantum Internet where all messages are sent via a few photons, and any attempt to intercept communication can always be detected.

However, the hardware to create the quantum Internet is not yet ready to be widely deployed, and there are challenges in sending messages over very long distances. China has built a land-based QKD communications network from Beijing to Shanghai, but because photons can be absorbed in the atmosphere or by materials in cables, they can typically travel for no more than a few kilometres. The Chinese have therefore had to create 32 so-called “trusted nodes” at various points along the network where keys are decrypted into classical form and then re-encrypted in a fresh quantum state for their journey to the next node.

A Dutch company called QuTech has become the first in the world to prove that quantum entanglement on demand is possible. In 2015, the QuTech team managed to entangle qubits 1.3 kilometres apart, but the connection could be established only once an hour and lasted for a fraction of a second. This June, they had entangled two electrons a couple of metres apart 40 times per second.

These advances have prompted the formation of the Quantum Internet Alliance (QIA) in Europe. The alliance aims to “build a quantum internet that enables quantum communication applications between any two points on Earth.” We are still years, if not decades away from a quantum Internet becoming a reality, but the current research provides hope that our communications (and all the personal data stored by companies) in the future will be far more secure.