Researchers at Stellenbosch University, working with the University of Science and Technology of China, have established the world’s longest ultra-secure quantum satellite link, a 12,900 km connection between Beijing and Stellenbosch. According to Stellenbosch University, it is the first quantum satellite communication link ever created in the Southern Hemisphere, with the findings published in the journal Nature in March 2025.
The intercontinental link spans 12,900 km, making it the longest secure quantum communication link ever created, according to the collaboration. The achievement marks a milestone for both South African science and global quantum communication research.
How the link was built
The team used China’s Jinan-1 microsatellite, which operates in low Earth orbit, to relay the quantum signal. A portable ground station was mounted on the roof of the engineering building at Stellenbosch University to receive the transmission.
According to the researchers, the first successful Beijing-Stellenbosch quantum key exchange took place in October 2024. The setup relied on local conditions that proved especially well suited to the task.
- The link spans 12,900 km, the longest secure quantum communication link ever created.
- It is the first quantum satellite communication link in the Southern Hemisphere.
- The portable ground station was mounted on the roof of the engineering building at Stellenbosch University.
- The first successful Beijing-Stellenbosch quantum key exchange took place in October 2024.
A record key generation rate
According to Stellenbosch University, the institution’s clear skies and low humidity helped the team achieve a record key generation rate of 1.07 million secure bits in a single satellite pass. These environmental conditions were central to the link’s performance.
The work was carried out as a collaboration between Stellenbosch University and the University of Science and Technology of China, with the results published in Nature in March 2025.
Why it matters
The link represents the first quantum satellite communication connection established in the Southern Hemisphere, extending technology that had previously been demonstrated in the Northern Hemisphere to a new part of the globe. By spanning two continents, the Beijing-Stellenbosch connection demonstrates that ultra-secure quantum communication can operate over intercontinental distances.
For Stellenbosch University, the achievement places South African researchers at the centre of an internationally significant advance in secure communication, built on a partnership with one of China’s leading science institutions.
Leave a Reply