India marked a significant milestone in its quantum technology journey with the successful demonstration of free-space quantum secure communication using entanglement at the DRDO-Industry-Academia Centre of Excellence (DIA-CoE), IIT Delhi. This landmark achievement was officially announced by the Ministry of Defence.
The experiment demonstrated quantum entanglement-based secure communication over a distance exceeding one kilometre on the IIT Delhi campus via a free-space optical link. The setup achieved a secure key rate of nearly 240 bits per second with a quantum bit error rate (QBER) below 7%, paving the way for secure real-time quantum cybersecurity applications, including Quantum Key Distribution (QKD), quantum networks, and the prospective quantum internet.
Under the DRDO-backed project ‘Design and development of photonic technologies for free space QKD’, the demonstration was led by Prof Bhaskar Kanseri’s team, with key DRDO officials, IIT Delhi leadership, and defence scientists present.
Quantum entanglement-based QKD offers superior security over conventional methods by ensuring that any interception attempt disturbs the entangled photons’ quantum state, alerting legitimate users. This technology is considered unbreakable by conventional means, offering immense potential in securing sensitive defence, financial, and telecommunications data.
This latest success builds upon India’s previous quantum achievements, such as the Vindhyachal-Prayagraj intercity quantum link (2022) and a 100-km quantum key distribution over telecom-grade fiber (2024). These developments are part of DRDO’s national initiative via 15 Centres of Excellence established in premier institutes like IITs and IISc.
Raksha Mantri Rajnath Singh lauded the development as a “game changer for future warfare and secure communications”, while DRDO Chairman Dr. Samir V Kamat and IIT Delhi Director Prof Rangan Banerjee congratulated the team for this leap into India’s “quantum era”.