Chinese researchers have developed a way to send uncrackable “quantum keys” between ground stations and low-orbit satellites, which is considered one of the most significant breakthroughs in the field.
In 2018, researchers from the University of Science and Technology in China (UTSC) devised a way to share quantum keys in secret between a series of ground stations and China’s Micius satellite – creating the largest secure quantum network on earth.
However, some kinks needed ironing out, according to science website, LiveScience. The quantum communication tool had a few leaks, which required the team to create a more sophisticated form of quantum encryption know as measurement-device-independent-quantum key distribution (MDI-QKD)
Now, scientists can pull off a wireless MDI-QKD without fibre optics – a world first. The next step is to send an MDI-QKD from their earth stations to Micius.
Quantum communication uses the principles of physics to protect data. The laws of physics dictate that particles, in this instance photons of light travelling through a medium, assume a state of superposition.
Taking on this state means that they can represent numerous combinations of 1 and 0 at the same time.
The ultra-tiny quantum bits (qubits) exist in such a fragile state that hackers and prying eyes have an incredibly difficult time trying to observe your data without it collapsing entirely.
Companies take advantage of this principle by creating networks to send sensitive data. These Quantum Key Distribution (QKD) networks are super-secure.
Daniel Oblak, a quantum communication researcher at the University of Ontario in Canada, said the results opened up the door to quantum-encrypted networks to use both fibre optic and satellite technologies working in tandem – an impossibility until now.
The team first tested their method between two stationary buildings, separated by 11.9 miles in the Chinese city of Hefei. They created a sophisticated algorithm to solve the riddle that atmospheric turbulence posed.
The next challenge is developing an algorithm that can account for the massive distance between the satellite and earth, according to Qiang Zhang, a research member.
Zhang said the team would have to figure out how to work the perpetual motion of the satellite’s orbit into their algorithm.
Wolfgang Tittel, a quantum communication expert at the University of Technology in the Netherlands, said the feat would be monumentally difficult to achieve but it is “plausible the USTC team will pull it off.”