India Enters New Quantum Era with DRDO-IIT Delhi’s Secure Free-Space QKD Demo

Unlike traditional quantum cryptography that uses “prepare-and-measure” schemes, the entanglement-assisted QKD approach significantly enhances both security and reliability.

India has marked a transformative milestone in its quest to become a global leader in quantum technology with the successful demonstration of free-space quantum secure communication using quantum entanglement. Spearheaded by the DRDO-Industry-Academia Centre of Excellence (DIA-CoE) at IIT Delhi, this experimental leap showcases India’s deepening scientific prowess in quantum-based cyber security.

The demonstration, conducted within the IIT Delhi campus, established a free-space optical link over one kilometre and achieved secure key distribution at 240 bits per second, maintaining a quantum bit error rate (QBER) below 7%. This achievement marks India’s most advanced real-world application of entanglement-assisted Quantum Key Distribution (QKD) to date and positions the country at the forefront of secure quantum communication.

Quantum Entanglement: A New Era in Cyber Defence

Unlike traditional quantum cryptography that uses “prepare-and-measure” schemes, the entanglement-assisted QKD approach significantly enhances both security and reliability. Even when devices are flawed or tampered with, the fundamental laws of quantum mechanics ensure that any eavesdropping attempt is instantly detectable.

This level of unbreakable encryption is vital for strategic sectors like:

• National Defence and Intelligence

• Financial Systems and Banking

• Telecommunications Infrastructure

• Critical Infrastructure Protection

The free-space approach also circumvents the costly and disruptive need to install underground fiber-optic cables—an especially important innovation for India’s diverse terrain and urban complexity.

Project and Technological Details

The experiment was conducted under the DRDO-funded project “Design and development of photonic technologies for free-space QKD”, sanctioned by the Directorate of Futuristic Technology Management (DFTM). It was led by Prof. Bhaskar Kanseri and his team at IIT Delhi, in the presence of senior officials, including:

• DG (MED, COS & CS), DRDO

• Director, Scientific Analysis Group (SAG)

• Director, DFTM

• Dean (R&D), IIT Delhi

• Director (DIA-CoE), IIT Delhi

• Scientists from DRDO labs

A Continuum of Quantum Achievements

India's growing quantum communications capability is part of a multi-year effort. In 2022, DRDO demonstrated India’s first intercity quantum communication link between Vindhyachal and Prayagraj, using underground optical fiber. In 2024, the same team successfully distributed entangled quantum keys over 100 km of telecom-grade optical fiber, another DRDO-supported milestone.

These advances contribute to the development of a quantum-secure communication infrastructure that will one day underpin the Quantum Internet, enabling not only encrypted messaging but also ultra-sensitive sensing and secure cloud computing.

Government Backing and Strategic Vision

India’s national quantum mission is being actualized through the DIA-CoEs, where 15 Centres of Excellence have been established in premier institutions like the IITs, IISc, and select universities. These centres serve as collaborative hubs bringing together academia, industry, and government to build frontier technologies for future warfare, civil use, and economic competitiveness.

Raksha Mantri Shri Rajnath Singh hailed the achievement as a game changer in future warfare and cyber defence, congratulating the DRDO and IIT Delhi teams for their remarkable work.

Dr. Samir V Kamat, Secretary, Department of Defence R&D and Chairman of DRDO, and Prof. Rangan Banerjee, Director of IIT Delhi, also extended their congratulations, recognizing this accomplishment as a key enabler in India’s push toward quantum sovereignty.

Road Ahead: India’s Quantum Leap

This demonstration solidifies India’s credentials as an emerging quantum power. The next stages are expected to include:

• Extending QKD range to tens or hundreds of kilometers via satellite links

• Integrating quantum security into defence and government communications

• Developing an indigenous quantum internet ecosystem

• Deploying start-up and industry collaboration for technology scale-up

With sustained investment, international collaboration, and a robust scientific ecosystem, India is now poised to play a decisive role in shaping the future of global quantum technologies.