Image Credit : PIB
DRDO & IIT Delhi Achieve 1 km Quantum Secure Communication
The Defence Research and Development Organisation (DRDO), in partnership with IIT Delhi’s Centre of Excellence, has successfully demonstrated quantum entanglement-based, free-space quantum secure communication over a distance exceeding 1 km at the IIT Delhi campus. This milestone marks a significant step toward India’s future quantum internet and cyber-security capabilities.
Free‑space quantum key distribution
The experiment achieved a secure key rate of nearly 240 bits per second, with a quantum bit error rate (QBER) below 7%, highlighting the reliability of this entanglement-enabled Quantum Key Distribution (QKD) system. By utilizing entangled photons, the system ensures that any eavesdropping attempt would disturb the quantum state—immediately alerting authorised users to potential intrusion.
Advantage over fibre-based systems
Unlike the conventional prepare-and-measure QKD methods, entanglement-based security enhances resilience even when device integrity is compromised. Moreover, free-space transmission avoids costly and disruptive optical fibre installations—particularly beneficial in dense urban or difficult terrain environments.
Future‑ready quantum networks
This demonstration supports India’s broader goal of building scalable quantum networks. It advances secure long-distance QKD, networks laid across cities, and lays the groundwork for an eventual quantum internet. It aligns with earlier achievements, such as:
- QKD over underground optical fibre between Vindhyachal and Prayagraj (2022).
- Entanglement-based QKD over 100 km of telecom-grade fibre (2024).
Strategic impact & next steps
Raksha Mantri Rajnath Singh hailed the breakthrough as heralding a “new quantum era” in secure communications—vital for future warfare, defence systems, financial networks, and telecom infrastructure. Under the DRDO–Industry–Academia Centres of Excellence framework (including IITs and IISc), India now operates 15 such hubs to foster cutting-edge defence technologies.
As the nation continues to develop photonic technology and quantum hardware for robust free-space QKD, this milestone brings India closer to deploying operational quantum-secure links—enhancing national cyber defence and enabling strategic secure communications.
