HEFEI, May 31 (Xinhua) -- Chinese scientists have set a world record for dual-field quantum key encryption (QKD) over a 1,002 km optical fiber cable. It is an important step towards building a large-scale quantum network in the future.

Quantum cryptographic key diffusion is the main method for quantum communication. Allows two remote users to create a shared encryption key that only they know. which is used to encrypt and decrypt messages

However, the application of quantum cryptographic key distribution faces a big problem: limited distance. This is because the quantum signal range cannot be expanded and the transmission of the communication channel decreases exponentially with distance.

Dual-field quantum key encryption has previously been demonstrated in the laboratory over an 830-kilometer (830-kilometer) fiberglass reel.

The study, published in the journal Physical Review Letters, said that scientists from institutions such as the University of Science and Technology of China. Jinan Institute of Quantum Technology Shanghai Institute of Microsystems and Information Technology It revealed that the longest distribution distance was 1,002 kilometers with a security key rate of 0.0034 bits per second.

Scientists have developed a range estimation of a dual-band, or two-wave device. and a superconducting nanowire single photon detector (SNSPD) during the experiment. To reduce system noise which hinders the production of security keys at a distance.

This study investigated the feasibility of dual-field quantum mechanical cryptographic key distribution over very long distances. and identifies opportunities for long-distance quantum communication - Xinhua News Agency

Source: Thai News Agency