India has demonstrated its first free-space Quantum Key Distribution (QKD) link over a distance of 5.56 km. The trial established a secure communication channel between the Bhaskaracharya National Institute for Space Applications and Geo-informatics (BISAG-N) under the Ministry of Electronics and Information Technology and Indian Institute of Technology (IIT) Gandhinagar.
Under testing, the system transmitted quantum signals through open air rather than fibre and maintained a stable connection, with a Quantum Bit Error Rate of below 5 per cent. It generated secure encryption keys at a rate of 230–260 bits per second, reports IANS, a partner of TV BRICS.
The keys were then used with the platform, which is designed to protect information using post-quantum cryptography. The system successfully encrypted and decrypted test messages, demonstrating that the technology can be used to securely exchange data.
The trial combined two methods of protecting information. Quantum Key Distribution helps create secure encryption keys using the properties of quantum physics, while post-quantum cryptography is designed to protect data against future threats from powerful quantum computers.
Vinay Thakur, Director General of BISAG-N, said the integration of the technologies supports the development of practical quantum-resilient communication systems.
Free-space quantum communication could be useful for links where laying fibre-optic cables is difficult. The technology also has potential for longer-distance and satellite-based communication, supporting India’s efforts to develop secure communications infrastructure.