India, Oct. 6 -- India has demonstrated its first free-space Quantum Key Distribution (QKD) link over a distance of 5.56 km, establishing a secure quantum communication channel between the Bhaskaracharya National Institute for Space Applications and Geo-informatics (BISAG-N) and the Indian Institute of Technology (IIT) Gandhinagar.

The field trial was conducted on the night of September 27-28 by quantum cybersecurity company QNu Labs in collaboration with BISAG-N and IIT Gandhinagar. The demonstration used QNu Labs' Pointing, Acquisition and Tracking (PAT) system to maintain the quantum communication link through free space.

The link maintained a Quantum Bit Error Rate (QBER) below 5% and generated secure keys at a rate of 230-260 bits ...