A monumental leap in global secure communication has been achieved as South Africa and China successfully established the world’s longest intercontinental quantum communication link. This trending technology milestone, announced in March 2025 following its achievement in October 2024, spans an impressive 12,900 kilometers, marking a pivotal moment for digital security and international collaboration.
This breakthrough is not only the longest quantum communication link established to date, surpassing the previous 7,600km record held within the Northern Hemisphere, but also the first of its kind in the Southern Hemisphere, and the first secure quantum connection between the Northern and Southern Hemispheres.
The Quantum Advantage: Unbreakable Security
At the heart of this secure connection lies cutting-edge technology known as Quantum Key Distribution (QKD). Unlike conventional encryption methods that rely on complex mathematical algorithms potentially vulnerable to future quantum computers, QKD leverages the fundamental laws of quantum physics to ensure unparalleled security. Information, encoded in single photons—tiny particles of light—is transmitted between a sender and a receiver. The inherent principle of quantum mechanics dictates that any attempt by an eavesdropper to intercept, copy, or measure these photons will inevitably disturb their quantum state, leaving an immediate and undeniable trace. This allows the communicating parties to detect any intrusion and discard compromised keys, ensuring that only undisturbed photons are used to create an ultra-secure encryption key.
A Global First: How the Link Was Forged
The historic link was forged through the strategic deployment of China’s Jinan-1 microsatellite, launched into low Earth orbit in July 2022, and a portable optical ground station situated at Stellenbosch University in South Africa. During a single pass of the Jinan-1 satellite over the Stellenbosch ground station, encoded photons were successfully transmitted, enabling real-time quantum key generation. The optimal environmental conditions in Stellenbosch, characterized by clear skies and low atmospheric humidity, proved ideal, allowing the South African ground station to achieve an exceptional key generation rate of 1.07 million secure bits during this single pass. To demonstrate the efficacy of the link, encrypted images, specifically that of the Great Wall of China and the Stellenbosch University campus, were securely transmitted between Beijing and the South African facility. The research findings underpinning this monumental achievement were subsequently published in the esteemed journal Nature.
Key Players and Their Pivotal Roles
This landmark achievement is a testament to years of dedicated research and international collaboration. On the Chinese side, the University of Science and Technology of China (USTC) played a leading role in the international team. Prominent figures like Professor Juan Yin, who led the Chinese research team for this project and was instrumental in developing China’s first quantum satellite, Micius, were central to its success. China’s long-standing commitment to quantum technology is further highlighted by the contributions of Professor Jian-Wei Pan, often dubbed the “Father of Quantum,” who spearheaded the development of the Micius satellite launched in 2016.
South Africa’s pivotal role was spearheaded by Stellenbosch University, which hosted the crucial ground station and contributed significantly to the collaborative research efforts. Researchers such as Dr. Yaseera Ismail and Professor Francesco Petruccione from Stellenbosch were key contributors. South Africa’s growing prowess in this field is also underscored by the South African Quantum Technology Initiative (SA QuTI), funded by the Department of Science, Technology, and Innovation (DSTI). SA QuTI aims to cultivate a globally competitive research environment and foster a local quantum technology industry, with a consortium of five universities, including Stellenbosch and the University of the Witwatersrand, driving these efforts.
Building Blocks of a Quantum Future
This latest feat builds on China’s pioneering work in space-based quantum communication, initiated with the launch of the Micius satellite in 2016. Micius previously demonstrated intercontinental quantum links, including a 7,600km connection between China and Austria. While Micius validated the core concepts, Jinan-1 represents a crucial advancement due to its miniaturized, low-cost design and its ability to integrate with portable ground stations, making widespread deployment more practical. Furthermore, China has already established a robust 2,000km terrestrial fibre-based quantum network connecting 32 trusted nodes across its major cities, laying critical groundwork for future global integration.
Implications for a Secure World
This top news development has profound implications across various sectors, promising a new era of ultra-secure communication. Industries like finance, defense, and healthcare stand to benefit immensely from communication systems resistant to even future quantum-computer-based cyber-attacks. For governments worldwide, it offers an unprecedented opportunity to bolster national security and to collectively establish global standards for responsible data transmission in the quantum age. The successful establishment of this link is a significant step towards the overarching vision of a fully integrated, secure, and global quantum internet – a network capable of enabling secure communication, distributed quantum computing, and enhanced sensing across continents. China has ambitious plans to launch a global quantum communication service by 2027, with intentions to collaborate further with BRICS nations, including South Africa, to realize this ambitious global network.
The Dawn of Unprecedented Security
The collaboration between South Africa and China on this quantum communication link marks a monumental achievement, pushing the boundaries of what is possible in secure data exchange. It signifies not just a technical record but a tangible step towards a future where privacy and security in global communication are fundamentally guaranteed by the laws of physics. As quantum technology continues to evolve, this historic partnership paves the way for a more interconnected and secure digital world, impacting everything from international diplomacy to everyday transactions.
