China and Russia set record for unhackable quantum communication 3,800km away

A team of Russian and Chinese scientists have collaborated and successfully tested the ability to transmit quantum information via satellite between two cities of these two countries, Moscow and Urumqi, with the promise of being unhackable.

Specifically, scientists successfully sent two images encrypted with quantum keys at a distance of 3,800 km from a ground station near Moscow to another station in Urumqi (Xinjiang, China) via a satellite called Mozi.

In 2021, scientists conducted experiments sending quantum information via underwater fiber optic cables, but this method lost many photons and some of the information being transmitted. In addition, the longest distance transmitted by land (via fiber optic cables) was only 1,000 km.

Since data loss does not occur in space, using satellites for transmission ensures information preservation, extending the range of quantum communications to thousands of kilometers.

Mozi, also known as "Micius", is a satellite managed by the Chinese Academy of Sciences. It has been in orbit since 2016 and enables two-dimensional research and quantum information flow between space and the surface.

Chinese and Russian scientists began collaborating in 2020. In March 2023, a full quantum communication test between two ground stations was completed. The most recent test used images encrypted with quantum keys and was conducted on December 14, 2023.

Quantum communication uses the principles of quantum mechanics to send information in such a way that if intercepted by a third party, the state of the photons involved will change, revealing the presence of a spy and letting both parties know that their communication may have been compromised. This helps ensure security and privacy.