China Claims ‘World Record’ In Quantum Communications (QSDC); Says Securely Transmitted Data Over 100 Km

Beijing’s ambition to revolutionize quantum communication looks to be succeeding, as Chinese scientists claim to have set a world record for the longest quantum secure direct communication (QSDC), transferring information securely over 100 Km (62 miles)

Long Guilu, the developer of quantum-based secure direct communication technology, and his team announced that they have achieved a new distance record by safely transmitting data over 100 Km (62 miles), reported SCMP.

The observations were published in the journal Light: Science & Applications in early April in an article titled “Realization of quantum secure direct communication over 100 Km fiber with time-bin and phase quantum states.”

Despite transmission speeds being slow (0.54 bits per second), the paper noted that it was a major improvement over Long’s previous record of 18.5 Km set in 2020, two decades after he devised the device that can identify and prevent eavesdropping threats. 

Long, a Tsinghua University physics professor and vice-president of the Beijing Academy of Quantum Information Sciences, noted the transmission speeds, saying they were good enough for phone calls and text messaging at roughly 30 Km. 

He claimed that the technology was ready to be integrated with standard encryption techniques to create a secure network with classical relay points.

“If we replace parts of the internet today, where more eavesdropping attacks happen, with quantum channels, those parts will have the added ability to sense and prevent eavesdropping, making communication even safer,” Long added.

A bank account password, for example, could be securely communicated between two devices 90 Km away using three 30 Km quantum channels connected by two relay points and protected by encryption, according to Long. 

The most notable aspect is that any eavesdropping attempt during quantum transmission would be spotted, whereas information at the relay points would be safeguarded by classical encryption. 

“The experiment shows that intercity quantum secure direct communication through the fiber is feasible with present-day technology,” the team noted, adding that the technique also has “great potential” to secure the 6G technology. 

The longest QSDC distance published before this breakthrough was 18.5 Km. “The rapid progress of quantum computing causes anxiety over the security of those traditional communications,” the Chinese quantum team wrote.

China’s Quantum Communication Advances

China has made strides in quantum technology’s industrial utilization. In recent years, it has made several quantum technological advances, such as the world’s first quantum satellite, a 2,000 Km quantum communication line between Beijing and Shanghai, and the world’s first optical quantum computing machine prototype. 

Additionally, one of Beijing’s aims for its 14th five-year plan, which ends in 2025, is to establish an intercity quantum demonstration network based on secure relays. In November of last year, the goal was also incorporated into the city’s international science and technology innovation center team the construction plans.

Although it’s unknown how much further Chinese researchers have progressed in quantum computing, the Pentagon’s 2021 report to Congress on China states that China “continues its pursuit of leadership in key technologies with significant military potential.”

According to the science journal Nature, the University of Science and Technology of China in Hefei conducted the first “definitive demonstration” of using quantum mechanics for computations that would be “prohibitively slow on classical computers” in 2020. 

While there have been no reports of it being used for military purposes, experts believe the technology could be used in the future by China’s armed forces. Quantum could help detect submarines and stealth aircraft among other “military vehicles,” said Heather West, a senior research analyst with market research firm IDC in the US state of Massachusetts. Quantum computing can break “classical algorithms” to check on another country’s military, she told VOA.

China has already concerned other countries by combining civilian and military assets as part of a Military-Civil Fusion Development Strategy, making it difficult for the rest of the world to predict when academic research will become a valuable resource for the People’s Liberation Army.

Satellite-based quantum key distribution – DLR Institute of Communications and Navigation, Germany

Meanwhile, other countries are working on this arena as well. Quantum computing is included in the AUKUS military technology sharing agreement between Australia, the United Kingdom, and the United States, which was unveiled in September last year.

According to the National Defense Industrial Association, the White House, National Science Foundation, and Department of Energy stated in August 2020 that they would grant $625 million over five years for quantum R&D.

Quantum computing and quantum communication are still in their early stages of development. For many years to come, none of this research will be of practical application. However, quantum technology has significant geopolitical implications: fully functional quantum networks might offer unhackable communication routes, and a potent quantum computer might theoretically overcome most of the encryption used to safeguard emails and Internet operations.