Archive · 4 Oct 2026
QNu Labs Demonstrates India's First 5.56-km Free-Space Quantum Link
QNu Labs, BISAG-N and IIT Gandhinagar tested a way to share secret keys through the air.
The two locations were 5.56 kilometres apart.
A tracking system helped keep the optical connection pointed in the right direction.
The trial reported a low error rate and made 230 to 260 key bits each second.
The keys were used with BISAG-N’s Vedic Kavach platform.
The teams successfully encrypted and decrypted test messages.
The system combines a quantum device with software designed to provide another layer of security.
The companies say this kind of link could help where fibre cables are hard to use and may support future satellite communication.
QNu Labs, BISAG-N and IIT Gandhinagar demonstrated a 5.56-km free-space Quantum Key Distribution link between their sites.
The trial used QNu Labs’ Armos QKD device and a Pointing, Acquisition and Tracking system to keep the optical link aligned.
The demonstration reported a Quantum Bit Error Rate below 5% and generated keys at 230–260 bits per second.
The keys were integrated with BISAG-N’s Vedic Kavach platform, and test messages were successfully encrypted and decrypted.
The companies said the approach could support communication where fibre is difficult to access and could help advance satellite-based links; a separate report cited QNu Labs’ 1,000-km fibre network and ₹200-crore funding round.
- Who
- QNu Labs, BISAG-N and IIT Gandhinagar.
- What
- They demonstrated a 5.56-km free-space Quantum Key Distribution link and used its keys to encrypt and decrypt test messages.
- When
- One report dates the field test to the night of 27–28 September 2026; another says the demonstration was announced on Saturday.
- Where
- Between the BISAG-N and IIT Gandhinagar sites in Gujarat, India.
- Why
- To demonstrate quantum-secure communication through free space and advance links that do not rely on a dedicated fibre connection.
- Link distance
- 5.56 km
- Reported Quantum Bit Error Rate
- Below 5%
- Reported key generation rate
- 230–260 bits per second
- QKD hardware
- QNu Labs’ Armos device
- Tracking system
- Pointing, Acquisition and Tracking system
- Software platform
- BISAG-N’s Vedic Kavach, described as post-quantum cryptography-enabled and incorporating quantum random number generation
- Other network reported
- A separate article says QNu Labs deployed a 1,000-km quantum-secure network over existing telecom fibre in April 2026.
- Reported funding
- ₹200 crore in a Series A1 round, according to a separate article.
