India, Oct. 3 -- QNu Labs, in collaboration with the Bhaskaracharya National Institute for Space Applications and Geo-Informatics (BISAG-N) and IIT Gandhinagar, has demonstrated what it describes as India's first free-space Quantum Key Distribution (QKD) link over a distance of 5.56 km.

The field trial, conducted on the night of September 27-28, established a secure quantum communication channel between BISAG-N and IIT Gandhinagar. Using QNu Labs' Pointing, Acquisition and Tracking (PAT) system, the trial achieved a stable Quantum Bit Error Rate (QBER) of below 5% and generated secure keys at a rate of 230-260 bits per second (bps).

The demonstration combined two complementary layers of quantum security: QNu Labs' hardware-based QKD sys...