New Delhi, October 3: QNu Labs, working with the Bhaskaracharya National Institute for Space Applications and Geo-informatics (BISAG-N) and IIT Gandhinagar, has demonstrated India’s first free-space quantum key distribution (QKD) link over a distance of 5.56 km. The trial set up a secure quantum communication channel between BISAG-N and IIT Gandhinagar, the Ministry of Electronics and IT said on Saturday.
The field trial was carried out on the night of 27–28 September. Using QNu Labs’ Pointing, Acquisition and Tracking system, it achieved a stable Quantum Bit Error Rate below 5% and generated secure keys at 230 to 260 bits per second (bps).
Quantum keys used to encrypt test messages
The keys were fed into BISAG-N’s Vedic Kavach platform, which supports post-quantum cryptography. Test messages were then encrypted and decrypted end to end.
The demonstration combined two layers of quantum security. One was QNu Labs’ hardware-based QKD device, Armos, working over free-space optical channels. The other was Vedic Kavach, BISAG-N’s software-based post-quantum cryptography with quantum random number generation. According to the ministry, this combined design keeps the system resilient even if the physical quantum channel is temporarily unavailable.
Longer links and satellite communication next
Vinay Thakur, Director General of BISAG-N, said bringing Vedic Kavach together with QNu Labs’ QKD technology was a significant step towards practical quantum-resilient communication systems.
Sunil Gupta, co-founder and CEO of QNu Labs, said the 5.56 km demonstration opens 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 gave a useful field setting for advancing practical quantum communication. It also showed how academia, indigenous technology and real-world testing could be combined to meet new secure communication needs, he said.
The partners behind the trial
BISAG-N is an autonomous scientific society under MeitY that works in space technology applications, satellite communication and geo-informatics, and supports technology-driven governance. IIT Gandhinagar was founded in 2008. QNu Labs, founded in 2016, builds quantum-secure digital infrastructure.
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