by Boladale Erogbogbo (’23) | May 10, 2021

Quantum internet systems may be a solution to the modern problem of failing cybersecurity. As technology continues to improve and everyday tasks become increasingly virtual, private information is frequently stored on the internet, where hackers and scammers alike roam free. Although we rely on these internet systems to protect our information and provide the convenience of instant communication, they aren’t fool-proof. Quantum internet systems, however, are. Attempts by physicists to change the current internet system itself may offer a greater level of privacy to the public than previously was possible.

Through extensive research and experimentation, researchers have created a means of communication that works by sending signals between quantum devices. In July 2018, University of Geneva’s Alberto Baoron and his colleagues successfully used quantum key distribution to send information to different quantum nodes. In other words, the group was able to send complex encrypted messages from one point to another. This was made possible by the use of qubits, which are like binary bits of information but function by transmitting quantum information. One node, or point, (Alice) would send qubits to another node that would measure them (Bob). Only certain measurements would allow Bob to calculate the same value for qubits as Alice, so Alice shares those measurements over a public channel. Bob and Alice are then able to freely communicate, but the actual values of the qubits themselves never have to be revealed: any attempt to intercept the network to discover the values would be flagged. Though this method of communication pales in comparison to the many functionalities of the modern internet, it is still an important step towards the creation of extremely secure systems of communication.

For this quantum system to work, devices that create and transmit entangled particles must be utilized. Entangled particles share something Albert Einstein called “spooky action at a distance” or a Yin- and Yang-like balance. Any attempt to measure or influence one particle also influences the other, which is why quantum networks are so secure. Breaches are easily detected, and users can efficiently switch to a different network for communication. Current applications of such entanglement include split photons. However, a downside of using photon particles is the difficulty in transmitting information over long distances. Like the light from a flashlight, photon waves fan out over long distances, making it difficult for receivers to intercept them. Researchers at Nanjing University have addressed this problem by using drones, like a chain of focusing lenses, to better transmit information to receivers over a distance. This involves a makeshift quantum communication system, in which a drone can transmit particles to a ground receiving station while also sending corresponding entangled particles through a different drone to another ground station one kilometer away. This drone system is not guaranteed to transmit photons to receivers, but it has improved retention.

Quantum internet communication is still very early in its development so far. Researchers like those at Nanjing University believe that the next steps are to scale communication to the size of a city and then use cheaper and more mobile devices like drones in areas less affected by air travel and pollution. As of right now, quantum systems cannot transmit sizable amounts of information but instead function on a much smaller scale, giving us a sneak peek into the level of advancement we can expect of technology in the next decade or so.