Illustration of the concept of quantum communication
Chinese researchers proposed a one-way quasi-QSDC (quantum secure direct communication) protocol with single photons and successfully developed a functional system, marking a transition of QSDC from theoretical research to real-world implementation. This technology has potential for adoption in sectors demanding the highest levels of information security, according to Xinhua News Agency on Saturday.
The research was conducted in collaboration with teams from the Beijing Academy of Quantum Information Sciences, Tsinghua University, and North China University of Technology. The related findings have been published in the academic journal Science Advances.
According to the report, QSDC was originally proposed by the team of Long Guilu, a professor from Tsinghua University. It utilizes quantum states to establish a secure communication framework, which incorporates five key attributes: eavesdropping detection, prevention, seamless network compatibility, streamlined management, and covert data transmission, offering an innovative approach to safeguarding data security in communications.
A major hurdle in QSDC development has been ensuring secure and reliable communication via quantum states, which have extremely low energy and are highly susceptible to interference, especially in quantum channels with high noise, high loss, and potential eavesdropping risks, said the report.
In previous research, the two communicating parties required the transmission of quantum states back and forth, resulting in significant system loss and severely limiting communication performance.
"In 2022, we set a world record for QSDC over 100 kilometers, but the rate was only 0.5 bps, which limited transmissions to extremely short messages," said Long to Xinhua.
Long said that one-way transmission can halve the distance of quantum state transmission, significantly reducing loss and serving as a key to improving the performance of QSDC.
In this research, teams overcame a series of key technical challenges, successfully achieving stable data transmission of 2.38 kilobits over a 104.8-kilometer standard fiber-optic network in a 168-hour experimental test. This represents a 4,760-fold improvement over the 2022 system, significantly advancing QSDC performance, Xinhua reported.
"This research achievement ushers in a new era for QSDC's practical applications. In the future, QSDC systems are expected to be widely used in fields such as government affairs and finance, which demand the highest levels of data protection, greatly strengthening data transmission security," said Long.
Global Times
