India has carried out its first demonstration of a free-space Quantum Key Distribution (QKD) link. The link stretched 5.56 km and connected the Bhaskaracharya National Institute for Space Applications and Geo-informatics (BISAG-N) with IIT Gandhinagar. QKD relies on the principles of quantum physics to exchange encryption keys in a secure manner. A free-space link carries these quantum signals through the open air instead of through optical fibre, and this trial is the country's first such link over that distance.