Quantum secure communication breakthrough for China scientists
- Technology inventor achieves new transmission distance of 100km and says it is suitable at shorter distances for audio calls and texts
- Replacing parts of the internet with quantum channels and relay points will make communication ‘even safer’
While transmission speeds were slow – at just 0.54 bits per second – it is a significant jump from Long’s 2020 record of 18.5km, two decades after he came up with the system, which can detect and prevent eavesdropping attacks.
The transmission speeds were good enough for audio calls and text messages at about 30km, according to Long, a physics professor at Tsinghua University and vice-president of the Beijing Academy of Quantum Information Sciences.
Long, co-leader of the research team which includes scientists from both institutions, is also a fellow of the American Physical Societies. He said the technology was ready to be combined with traditional encryption methods to form 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 said that for example, a bank account password could be securely sent between two machines 90km apart, through three 30km quantum channels joined by two relay points, protected by encryption.
Any eavesdropping attack would be detected if it was attempted during quantum transmission, while the data would be protected by classical encryption at the relay points, he said.
Long and his team published their findings this month in Light: Science & Applications. The peer-reviewed journal is co-published by Changchun Institute of Optics, Fine Mechanics and Physics, and Nature Publishing Group.
“The experiment shows that intercity quantum secure direct communication through fibre is feasible with present-day technology,” they wrote, adding the system also has “great potential” for secure 6G wireless communication.
The building of an intercity quantum demonstration network based on secure relays is one of the capital city Beijing’s goals for its 14th five-year plan which ends in 2025.
The ambition was added to the city’s international science and technology innovation centre construction plans in November last year.
Chinese scientists may be a step closer to a quantum code-breaking machine
To counter potential quantum computing attacks, classical cryptographic algorithms have been developed, called post-quantum cryptography, as well as a quantum key distribution system.
“The rapid progress of quantum computing causes anxiety over the security of those traditional communications,” the Chinese quantum team wrote.
