New Delhi: With the successful demonstration of quantum entanglement-based free-space secure communication, India has taken a decisive leap into the quantum technology. The demonstration was conducted jointly by the Defence Research and Development Organisation (DRDO) and IIT Delhi.
Carried out at the DRDO-Industry-Academia Centre of Excellence (DIA-CoE) on the IIT Delhi campus, the experiment, achieved secure quantum communication over a distance exceeding one kilometre.
Facilitated via a free-space optical link, the milestone, recorded a secure key rate of nearly 240 bits per second with a quantum bit error rate below 7%. This sets the stage for real-time applications in quantum cybersecurity, long-distance Quantum Key Distribution (QKD), and the broader vision of developing quantum networks and a future quantum internet.
Titled ‘Design and development of photonic technologies for free space QKD’, the project is sanctioned by the Directorate of Futuristic Technology Management (DFTM), DRDO. The demonstration was led by Prof Bhaskar Kanseri’s research group and witnessed by senior officials including DRDO’s DG (MED, COS & CS), Director SAG, Director DFTM, and senior faculty from IIT Delhi.
Quantum entanglement-based communication, unlike traditional prepare-and-measure QKD systems, ensures higher security — even when hardware may be compromised. Any eavesdropping attempt alters the entangled quantum state, making it detectable. It also bypasses the need for laying costly and disruptive optical fiber networks, particularly beneficial in remote or urban areas.
The successful demonstration builds on previous achievements, including India’s first intercity quantum communication link between Vindhyachal and Prayagraj in 2022, and a 100-km fiber-based quantum key distribution demonstration in 2024. All efforts are anchored within DRDO’s DIA-CoEs, which now span 15 premier academic institutions across the country.
Defence Minister Rajnath Singh congratulating the team, said, “India has entered into a new quantum era of secure communication which will be a game changer in future warfare.”
Echoing the sentiment, DRDO Chairman Dr Samir V Kamat and IIT Delhi Director Prof Rangan Banerjee commended the breakthrough as a critical step towards national security and technological sovereignty.
