India demonstrated its first 5.56 km free-space quantum key distribution link today (3 October), marking a significant advancement in the country’s quantum communication capabilities.
The trial was conducted by QNu Labs in collaboration with Bhaskaracharya National Institute for Space Applications and Geo‑informatics (BISAG‑N) and IIT Gandhinagar.
The achievement, announced by the Ministry of Electronics and Information Technology, represents the longest atmospheric quantum communication link established in India without relying on fibre-optic infrastructure.
The field trial, conducted on the night of 27-28 September, established a secure quantum communication channel between BISAG‑N and IIT Gandhinagar.
Using QNu Labs’ Pointing, Acquisition and Tracking system, the trial achieved a stable Quantum Bit Error Rate below 5 per cent and generated secure keys at a rate of 230–260 bps.
These keys were integrated with BISAG‑N’s post‑quantum cryptography enabled Vedic Kavach platform, enabling successful end‑to‑end encryption and decryption of test messages.
The demonstration combined two complementary layers of quantum security: QNu Labs’ hardware‑based QKD device Armos over free‑space optical channels and BISAG‑N’s Vedic Kavach software‑based post‑quantum cryptography with quantum random number generation.
This integrated architecture ensures resilience even if the physical quantum channel is temporarily unavailable.
