Quantum cryptography advances through research and secure network demonstrations

Researchers have achieved a significant breakthrough in quantum cryptography by securing Discrete-Modulated Continuous-Variable Quantum Key Distribution (DM CV-QKD) over distances exceeding 70km. Previously, this protocol struggled to provide secure keys beyond approximately 25km under similar conditions. A team from the University of Waterloo and collaborating institutions developed new theoretical tools, including an infinite-dimensional marginal-constrained entropy accumulation theorem, to provide a complete security proof against coherent attacks under realistic conditions.

In a separate practical application, Babcock International Group and Arqit Quantum Inc demonstrated a secure communications network designed to defend against future quantum-enabled threats. During a demonstration at DVD 2026, Arqit’s encryption software was used to securely transmit scenario data to Babcock’s Ground Deployed Advanced Mortar System (GDAMS). The demonstration showcased the ability to exchange critical operational information between a headquarters and a deployed platform in contested environments using layered encryption across various network bearers like 4G/5G, Wi-Fi, and satellite communications.