For the very first time, a quantum encrypted message was transmitted through the air in an urban environment. The message contained slightly over one bit of data and shows that it could indeed be a reality when high-capacity communications could be done using free-space quantum security. This could be the beginning of a new era of extremely secure, stable, and high capacity networks that could be used for communications between satellites and ground stations.
Understanding Quantum Encryption
Quantum encryption is a new and currently only experimental way to encode information in bits of quantum data. The more rudimentary forms of quantum encryption involve 2D encryption, where individual photons are used to encode each bit in binary. So far, scientists have been successful in 2D encryption and are also showing that it is possible to encode even more data on each photon, which would make it high-dimensional data encryption. This however, has not been possible to reproduce in a free-space environment, making the attempts so far failures.
Building Towards Free-space Quantum Networks
The lead researcher for the team from the University of Ottawa, Ebrahim Karimi, stated that their initial attempts involved transmitting data securely using high-dimension quantum encryption in closed spaces, the moving he systems into free-space to expose the signals to external disturbances, such as obstacles and turbulence. Through iterations they managed to eventually demonstrate that it is possible to achieve this. He also added that this could help others to form strong communication links between the Earth and our satellites.
Additionally the communications would be highly secure as intercepting the quantum signals to read them would cause them to get destroyed, thereby safeguarding the data they carry. This can be a highly beneficial way to securely maintain connection between locations without the use of very expensive fiber optics, or even between ground stations and moving aerial objects such as planes.