The DRDO–IIT‑Delhi collaboration, through the Defence Research & Development Organisation’s DIA‑CoE initiative, has successfully demonstrated free-space quantum entanglement-based secure communication over a distance exceeding 1 kilometre on the IIT‑Delhi campus. This experimental setup achieved a secure key rate of ~240 bits/sec and a quantum bit error rate (QBER) < 7%
Defence Minister Rajnath Singh praised the milestone, calling it a “game‑changer” in future warfare and declaring that India has entered a new quantum era of secure communication
🔬 Why Entanglement-Based QKD Matters
- Advanced security: Overcomes limitations of “prepare-and-measure” models by enabling detection of eavesdropping through entanglement disruption
- Device robustness: Security holds even when equipment is imperfect. Any tampering introduces detectable anomalies
- No fibre needed: Free-space links avoid buried infrastructure, ideal for mobile, battlefield, or urban environments
📈 Build-Up: The Road So Far
- 2022: DRDO & IIT‑Delhi built India’s first 100 km QKD link over fiber between Prayagraj and Vindhyachal
- 2024: Entanglement-based 50 km laboratory QKD over fiber and free-space QKD over 80 m were achieved
- Oct 2023: IIT‑Delhi set a global record with 380 km fiber QKD using DPS protocol
🌐 Broader Implications for India
- Strategic assistance: Supports secure military communications, quantum key exchange, and future quantum internet deployment
- Cybersecurity boost: Offers unhackable encryption for critical domains like defence, finance, telecom, and IoT
- Indigenisation drive: Developed India‑made photon sources, detectors, and entanglement tech—reducing dependence on imports
- Builds on National Quantum Mission: Aligns with DST’s ₹6,000 cr effort to advance quantum communication & satellite QKD, making India globally competitive
🚀 What’s Next?
- Extend free-space QKD beyond 1 km and integrate fiber and free-space networks.
- Lay groundwork for battle-ready, long-distance quantum communication.
- Advance toward satellite-based QKD, planned by ISRO within 2–3 years, per the National Quantum Mission roadmap indiatoday.in
Why It Matters
This breakthrough positions India at the forefront of quantum-secure communication. With entanglement-assisted QKD over long free-space distances, India is paving the way for unbreakable military-grade encryption, safeguarding national infrastructure, and laying the groundwork for a quantum internet era.
