Latest news with #QSDC
South China Morning Post
3 days ago
- Politics
- South China Morning Post
China scientists put direct quantum communications tech to test in space flight
China has tested how the core components of a quantum-based network might withstand the rigours of space travel, in what is believed to be the start of efforts to build an integrated space-ground system for ultra-secure communications that do not need encryption keys. A laser module and a phase encoding device, developed at the Beijing Academy of Quantum Information Sciences, were on board a Yuanxingzhe-1 rocket that reached 2.5km (1.55 miles) during a two-minute vertical flight testing its reusability last Thursday. 'The launch mainly tested the robustness of the modules against various environmental stresses encountered during rocket ascent, such as vibration and radiation,' the academy said on its official social media account on Wednesday. The test marked a key step in China's transition from experimental validation to the construction of a fully integrated space-air-ground quantum secure direct communication (QSDC) network, the academy added. First proposed by Chinese physicists in 2002, QSDC is considered complementary to another form of quantum secure communication, known as quantum key distribution (QKD). While QKD involves generating encryption keys for use over conventional communication channels, QSDC skips the key-sharing step and sends the actual message directly through a quantum channel. This makes the system more efficient and, in principle, more secure, which has led to some experts referring to QSDC as the 'ultimate form' of secure communication.
South China Morning Post
5 days ago
- General
- South China Morning Post
China team triples distance record set by direct quantum communication founder
Chinese scientists have achieved a record in quantum-based secure direct communications – trebling the distance of a multi-user network to around the same length as a drive from Paris to Brussels, according to a new paper. While the transmission rate is still too low to handle images, the researchers at Shanghai Jiao Tong University said the 300km (186 miles) optical fibre network was theoretically scalable, showing the viability of this kind of quantum network. According to the paper, published in the May issue of the peer-reviewed Science Bulletin, the quantum secure direct communication (QSDC) network uses multiple lasers or pumps to send paired photons between users, with added noise to help hide the signals. 'The transmission distance or the number of users acts as a constraint on the construction of long-distance, large-scale quantum communication networks,' the researchers said in the paper. 'The realisation of a 10,000km-level quantum communication network containing hundreds or thousands of users represents a significant challenge that requires urgent attention,' they added. There are three main forms of communication that take advantage of quantum physics phenomena to securely send data using particles – typically photons – along optical fibre cables.
South China Morning Post
25-02-2025
- Science
- South China Morning Post
Back to the future: Chinese team's record transmission lays ground for quantum internet
Chinese scientists have set a transmission record in quantum secure direct communication, which brings the technology to the internet dial-up speed of the 1990s and sets the stage for a future quantum internet. Advertisement The team's new quasi-quantum secure direct communication (QSDC) protocol set both a transmission and a distance world record with a transmission rate of 2.38 kilobits per second (kbps) over 104.8km (65 miles) of standard telecommunications optical fibre. This speed allows for the secure transmission of text, voice, and image files in quantum states, making it potentially useful for securely sending small amounts of sensitive information – such as financial data or information vital for national security. 05:00 Does the arrival of China's low-cost DeepSeek mean the end of Nvidia's chip dominance? Does the arrival of China's low-cost DeepSeek mean the end of Nvidia's chip dominance? 'This system paved the way for the practical application of QSDC and offers a unique method to detect eavesdropping online, which is crucial in certain circumstances,' the team wrote in a paper published in the peer-reviewed journal Science Advances on February 21. Inventor of the QSDC technology Long Guilu, a physics professor at Tsinghua University and vice-president of the Beijing Academy of Quantum Information Sciences, said the protocol could also be used for constructing a quantum internet. Unlike the classical internet, in which information is transmitted as bits, a quantum internet would aim to enhance internet capabilities and security by leveraging quantum bits, or qubits, and quantum phenomena to achieve ultra-secure connection. Advertisement 'Prototype quantum internet based on this protocol has already been built in our lab,' Long said.
