By successfully demonstrating free-space quantum secure communication using quantum entanglement over a distance of more than one kilometer at the IIT-Delhi campus, India achieved a major milestone in the field of quantum technology.
Defence Minister Rajnath Singh is hailing this breakthrough as a “game-changer in future warfare.” It was made by the Defence Research and Development Organisation (DRDO) in partnership with IIT-Delhi’s DRDO-Industry-Academia Centre of Excellence (DIA-CoE) and marks a significant step into the quantum era.
The experiment established a secure quantum key rate of roughly 240 bits per second with a quantum bit error rate below 7% by using lasers to send entangled photons through the open air. Since any interception alters the photons’ quantum state and warns users of unwanted access, entanglement-assisted quantum secure communication enables immediate detection of any eavesdropping attempts. Particularly in difficult terrain and crowded urban settings, the use of free-space optical links rather than conventional fiber optic cables speeds up and lowers the cost of deployment.
This accomplishment opens the door for real-time quantum cybersecurity applications, such as long-distance QKD, quantum network development, and the eventual quantum internet. Since quantum communication is thought to be inherently unbreakable, it provides strong security for vital industries like telecommunications, finance, and defense. The technology can be used for both national security and civilian purposes.
The Directorate of Futuristic Technology Management (DFTM), DRDO, approved the project, which was headed by Professor Bhaskar Kanseri’s research group and was named “Design and Development of Photonic Technologies for Free Space QKD.” A 100 km fiber-based quantum key distribution experiment in 2024 and India’s first intercity quantum communication link between Vindhyachal and Prayagraj in 2022 are two examples of prior accomplishments that this demonstration builds upon.
These technologies’ continuous development is a component of a larger DRDO initiative, which established 15 Centers of Excellence at prestigious universities throughout India to promote state-of-the-art defense technologies. In addition to solidifying India’s position as a leader in quantum technology, this most recent achievement lays the groundwork for a national quantum internet and next-generation secure communication systems.
