A team of scientists from Peking University has developed a prototype quantum communication network capable of spanning more than 3,700 km (2,300 miles). This innovative model was detailed in a study published in the journal Nature. The breakthrough could enable ultra-secure communications across vast distances. Current quantum key distribution (QKD) methods face challenges such as limited range, high equipment costs, and inefficient support for multiple users. Existing systems depend on "trusted relay nodes," or stations that manage quantum keys throughout the network route. However, these nodes pose potential security risks, similar to packages being handled at multiple points before delivery. The new model from Peking University aims to bypass these weak points and offer safer, longer-distance quantum communication.