China successfully sent quantum images to the opposite side of the Earth using a super-small satellite. By significantly reducing satellite costs compared to the past, the communication distance was drastically increased, marking the dawn of a full-fledged quantum communication era.
Pan Jianwei, a professor at the University of Science and Technology of China, announced on the 20th that a quantum communication experiment was successfully conducted over a distance of about 13,000 kilometers from Beijing, China, to South Africa using the super-small satellite 'Jinan-1.' The research results were published in the international journal 'Nature' on the same day.
Quantum communication is a technology that securely transmits information using the principles of quantum mechanics, which apply to the microscopic world. In quantum mechanics, the moment an observation is made, the subject changes, making hacking impossible. Quantum communication is primarily exemplified by Quantum Key Distribution (QKD). This technology allows the sender and receiver to share a quantum state password key, and if a third party attempts to eavesdrop, the quantum state is immediately altered, enabling real-time detection of eavesdropping, resulting in very high security.
Quantum communication's commercialization potential has already been demonstrated and is currently utilized in some government agencies and banks using wired methods with fiber optics. However, fiber optics absorbs some light (photons), thus limiting long-distance communications to over 200 kilometers. To overcome these limitations, wireless quantum communication that transmits photons through the air, especially using satellite technology, is actively being developed.
The research team transmitted a quantum encryption key from the rooftop of a building in Beijing to the rooftop of Stellenbosch University in South Africa using the Jinan-1 satellite. The receiver successfully decrypted the encrypted image using the encryption key. QKD using Jinan-1 showed an improved generation speed and efficiency compared to existing satellites, proving that stable quantum key transmission across the opposite side of the Earth is possible.
In particular, the economic feasibility of quantum communication has also improved. The Jinan-1 satellite used in this instance is ten times lighter and 45 times cheaper than 'Micius,' the world's first quantum communication satellite launched by China in 2016. Ground receiving equipment has also been miniaturized from the previous weight of 13 tons to 100 kilograms.
Earlier, Professor Pan Jianwei succeeded in wireless quantum communication over a distance of 2,600 kilometers within China using Micius in 2017. The following year, he also achieved transcontinental quantum communication between northeastern Beijing and Graz, Austria, which is about 7,600 kilometers away. This time, the communication distance was nearly doubled.
Yoon Cheon-joo, Deputy Minister of the Quantum Technology Research Institute at the Korea Electronics and Telecommunications Research Institute (ETRI), noted, 'China has already brought quantum communication technology to the commercialization stage through large-scale government-led investments' and added, 'Currently, efforts are focused on the miniaturization and practical application of quantum modules.'
In Korea, research on quantum communication is also being actively pursued. ETRI is developing 'quantum communication integration module' technology to revitalize the quantum communication industry and has announced a palm-sized 'CFP2 module.' This module is evaluated to have high commercialization potential as it supports both wired and wireless formats while being easy to apply to communication networks.
Deputy Minister Yoon stated, 'The quantum communication integration module is technically very challenging, which gives us a competitive edge,' and added, 'Once the related industry is fully activated, Korea could leap to become a leader in technology.'
References
Nature (2025), DOI: https://doi.org/10.1038/d41586-025-00581-7