New Record Set for Side-Channel-Secure Quantum Key Distribution

A recent experimental demonstration of side-channel-secure quantum key distribution (SCS-QKD) achieved a new distance record of 200 km. The research, conducted by a team from Nanjing University of Posts and Telecommunications, utilized an imperfect whole-space source and rigorous finite-key analysis. This advancement allows for high-speed secure key rates of 18.31 kbps at 100 km, 2.55 kbps at 150 km, and 196.03 bps at 200 km. The study addresses challenges such as imperfect vacuum preparation and finite-key constraints under coherent attacks. The results indicate significant progress in practical implementations of quantum key distribution, which is crucial for enhancing cybersecurity measures. The work was supported by various grants and involved contributions from multiple researchers. No competing interests were declared by the authors.

Key Points: • SCS-QKD achieved a new distance record of 200 km with high secure key rates. • The study utilized an imperfect whole-space source and rigorous finite-key analysis. • This advancement addresses critical challenges in quantum key distribution implementations.