- India's first free-space Quantum Key Distribution link at 5.56 km has been demonstrated
- The field trial ran on the night of September 27–28 between BISAG-N and IIT Gandhinagar
- Quantum Bit Error Rate stayed below 5%, with secure keys generated at 230–260 bps
- Vedic Kavach used the keys for successful end-to-end encryption and decryption of test messages
- Officials said the trial lays groundwork for longer-distance and satellite-based quantum communication
India has demonstrated its first free-space Quantum Key Distribution (QKD) link over 5.56 km, with the trial run from BISAG-N to IIT Gandhinagar. QNu Labs led the effort with BISAG-N and IIT Gandhinagar.
Night trial sets up secure channel
The field trial took place on the night of September 27–28. It set up a secure quantum communication channel between BISAG-N and IIT Gandhinagar.
QNu Labs used its Pointing, Acquisition and Tracking system to hold the link. The Quantum Bit Error Rate stayed below 5%. Secure keys were generated at 230–260 bps.
Two layers of protection
The keys were fed into BISAG-N’s post-quantum cryptography platform, Vedic Kavach. The team then carried out end-to-end encryption and decryption of test messages, and both steps worked.
The setup combined QNu Labs’ hardware-based QKD device, Armos, over free-space optical channels with Vedic Kavach’s software-based post-quantum cryptography. The software side also uses quantum random number generation.
The combined design is meant to keep communication secure even if the physical quantum channel goes down for a while.
What officials say next
Dr. Vinay Thakur, Director General of BISAG-N, said the integration of Vedic Kavach with QNu Labs’ QKD technology is a significant step towards practical quantum-resilient communication systems.
Sunil Gupta, Co-founder and CEO of QNu Labs, said the 5.56 km demonstration paves the way for longer-distance quantum-secure networks and satellite-based quantum communication.
Cmde Manish Tripathi (Retd.), In-charge of ISTF at IIT Gandhinagar, said the trial offers a useful field environment for advancing practical quantum communication. He added that it shows how academia, indigenous technology and real-world testing can work together.
The trial lays a foundation for India’s secure communication infrastructure and its defences against emerging quantum-era security threats.
