Science TechnologySunday, 4 October 2026·The Hindu - Science
India’s first free-space quantum key distribution link demonstrated over 5.56 km between BISAG-N and IIT-Gandhinagar
Indian scientists demonstrated India’s first free-space QKD link over 5.56 km on 27-28 September 2026 between BISAG-N and IIT-Gandhinagar.
Key highlights
Direct fact
On the night of 27-28 September 2026, Indian scientists demonstrated India’s first free-space quantum-key distribution (QKD) link over 5.56 km between BISAG-N and IIT-Gandhinagar, using equipment supplied by QNu Labs of Bengaluru.
Key specifics
- QKD uses photons to generate a shared encryption key and can detect interception through quantum-state errors.
- The demo achieved a quantum bit error rate of under 5%, which the Ministry of Electronics and IT described as desirable.
- The system generated secure-key information at 230-260 bits per second and successfully encrypted and decrypted messages.
- Earlier Indian demonstrations included IIT-Delhi and DRDO in 2025 over just above 1 km of free air, and ISRO over 300 m four years earlier.
- The National Quantum Mission targets satellite-based secure quantum communications up to 2,000 km and a 2,000-km inter-city QKD network over fibre-optic cables.
Exam lens
TNPSC may ask technology matching or mission-based questions; remember BISAG-N, IIT-Gandhinagar, 5.56 km, under-5% error rate, and the National Quantum Mission’s 2,000-km targets.