China set a record of 12,900 km long quartet communications

The road connecting the ground stations at the University of Science and Technology of China (USTC) in Beijing and Stellenbosch University in South Africa, through small quantum satellite named Jinan-1 and take advantage of quantum physics to create an “indefinitely” encryption, New Atlas On March 28 reported.

The information itself is classic information, including the image of the Great Wall in China and Stellenbosch’s photo, but encoded through the method of distributing quantum lock (QKD). The satellite encodes the password lock into individual photons, then transmits them to each ground station. After both sides have locks, stations can communicate safely via satellites.

The password lock is encoded according to the quantum state of the photon, due to the quantum effect, also known as the “ghost effect from afar”, the state changes as soon as anyone tries to observe them. In fact, this means that if the third party tries to access and read the transmission data, their actions will change the quantum state of the photon and disturb the message. As a result, data is not only useless to hackers but also warns the recipient about infringement.

Basically, the above method cannot be invaded by being protected by the law of quantum physics. In the current test, satellites can transmit more than 250 million quantum photons per second, creating more than one million safety locks in just one transmission from the satellite to the ground station. The distance of more than 12,900 km between the two ground stations set a new record for the distance for quantum communication.

Previously, it was the research team that successfully transmitted information in QKD between China and Austria over 7,600 km. That achievement was made by the older satellite called Micius. Jinan-1, launched in 2022, not only stronger but much smaller, only 1/10 of its predecessors. The ground stations are also significantly smaller from 13 tons to 100 kg. Satellite and smaller ground stations can help build safer and faster quantum Internet worldwide.