The researchers predict that the high-performance method will be widely used in upcoming intercity quantum communication networks.
Chinese researchers have created a high-performance quantum key distribution technique that advances the development of a telecom fibre-based quantum communication network.
According to Monday’s issue of Science and Technology Daily, researchers from Tsinghua University and the University of Science and Technology of China successfully realized experimental mode-pairing quantum key distribution.
An unhackable method of exchanging encrypted messages between remote users, quantum key distribution is based on a physical property of quantum mechanics that makes it impossible to create an independent and identical copy of an arbitrary unknown quantum state.
In China, metropolitan- and intercity scale quantum key distribution networks based on telecom fibres have been put into use. According to the researchers, the exponential decay of the key rate with respect to transmission distance has been viewed as a bottleneck.
In a recent study that was published in the journal Physical Review Letters, the researchers showed how a simpler, more affordable method of achieving a significant key-rate improvement when dealing with metropolitan and intercity distances could be achieved.
The study found that using 407 km of ultralow-loss fibre and 304 km of commercial fibre significantly improved key rate performance. The researchers predict that the high-performance method will be widely used in upcoming intercity quantum communication networks.
Quantum Key Distribution (QKD) secures keys over an insecure communication channel by exploiting the principles of quantum mechanics. In QKD, a sender encodes a key into a series of quantum states and transmits them to a receiver.
The receiver measures the quantum states to extract the key, and the laws of quantum mechanics ensure that any attempt to intercept the key will cause noticeable changes in the quantum states, alerting the receiver to the presence of an eavesdropper.
This makes QKD a highly secure method of exchanging cryptographic keys, and it is widely seen as a promising technology for securing communications in the age of quantum computers.