India Enters New Quantum Era with Breakthrough in Free-Space Quantum Communication
In a landmark achievement, India has successfully demonstrated free-space quantum secure communication using quantum entanglement, marking a major step forward in the nation's quantum technology capabilities. This experimental advancement, led by researchers from IIT Delhi in collaboration with the Defence Research and Development Organisation (DRDO), paves the way for real-time applications in quantum cyber security and positions India prominently in the global quantum technology race.
The experiment, conducted on the IIT Delhi campus, achieved quantum key distribution (QKD) over a distance of more than one kilometre, via a free-space optical link. The system achieved a secure key rate of nearly 240 bits per second with a quantum bit error rate (QBER) of less than 7%, demonstrating a technically robust and secure communication link. Defence Minister Rajnath Singh hailed the achievement as a “game-changer” for future warfare and a stepping stone into a new quantum era.
Unlike traditional cryptographic methods, quantum communication systems offer unbreakable encryption, grounded in the laws of quantum mechanics. Any interception attempt disturbs the quantum state of entangled photons, alerting the legitimate users and ensuring absolute security. This makes quantum entanglement-based Quantum Key Distribution (QKD) a more secure and reliable approach than the traditional prepare-and-measure method, especially in sensitive sectors such as defence, finance, and telecommunications.
The project titled “Design and development of photonic technologies for free space QKD” was sanctioned by the Directorate of Futuristic Technology Management (DFTM), DRDO. The demonstration was carried out by Prof Bhaskar Kanseri’s research group under the DRDO-Industry-Academia Centre of Excellence (DIA-CoE) framework. The free-space QKD system eliminates the need for expensive and intrusive optical fibre installations, making it ideal for difficult terrains and urban environments.
This successful demonstration is part of India’s broader efforts to advance quantum technologies for national development. It follows earlier achievements, including India’s first intercity quantum communication link between Vindhyachal and Prayagraj in 2022 using dark optical fibre, and a 100 km quantum key distribution using telecom-grade fibre in 2024. These initiatives underscore India’s commitment to developing indigenous quantum solutions through collaborative research.
Globally, nations like China, the United States, and the European Union are heavily investing in quantum networks. India’s ground-based free-space approach offers a complementary solution that can be strategically deployed in border regions or areas vulnerable to cyber threats.
This breakthrough enhances India’s stature in quantum research and lays the foundation for a future quantum internet, enabling secure, real-time communications that are resilient against all forms of spying, including threats posed by quantum computers.
