A 5.56-kilometre free-space quantum key distribution link was demonstrated between BISAG-N and the Indian Institute of Technology Gandhinagar during a field trial on the night of 27–28 September, India's Ministry of Electronics and Information Technology said in a 3 October release.
The trial involved QNu Labs, BISAG-N and IIT Gandhinagar. According to the ministry, it produced secure keys at 230–260 bits per second with a quantum bit error rate below 5 per cent. The team used the keys with BISAG-N's post-quantum cryptography platform to encrypt and decrypt test messages.
Quantum key distribution is a method for sharing encryption keys using properties of light. This was a reported field demonstration, not a rollout of a public communications network. The ministry said the combined approach could help guide future work on quantum-resilient communications.
Source: Press Information Bureau, Ministry of Electronics and Information Technology (3 October 2026).
Illustration disclosure: The accompanying image is an AI-generated conceptual editorial illustration of an optical communication link. It does not show the actual trial sites or equipment.
