India has taken a monumental step toward becoming a global leader in quantum technology by successfully demonstrating free-space quantum secure communication using quantum entanglement over a distance of more than one kilometer. This groundbreaking achievement, accomplished through the DRDO-Industry-Academia Centre of Excellence (DIA-CoE) at IIT Delhi, marks a significant milestone in India’s pursuit of advanced quantum cyber security and the development of a future quantum internet. Conducted on the IIT Delhi campus, this experiment showcases India’s growing prowess in quantum communication and its potential to revolutionize secure data transmission for strategic sectors.
Under the project titled Design and Development of Photonic Technologies for Free Space Quantum Key Distribution (QKD), sanctioned by the Directorate of Futuristic Technology Management (DFTM), DRDO, the research group led by Prof Bhaskar Kanseri achieved a secure key rate of nearly 240 bits per second with a quantum bit error rate of less than 7%. The demonstration utilized a free-space optical link, enabling quantum entanglement-assisted secure communication over a kilometer-long distance.
The experiment was witnessed by distinguished dignitaries, including the DRDO Director General (MED, COS & CS), Director SAG, Director DFTM, Dean (R&D) IIT Delhi, Director (DIA-CoE), and DRDO laboratory scientists. This success builds on earlier milestones, such as India’s first intercity quantum communication link between Vindhyachal and Prayagraj in 2022 using commercial-grade underground dark optical fiber, and a 2024 demonstration of quantum key distribution over a 100 km spool of telecom-grade optical fiber.
Quantum Key Distribution (QKD) using quantum entanglement offers unparalleled security compared to traditional prepare-and-measure methods. By leveraging the principles of quantum mechanics, entangled photons ensure that any attempt to intercept or measure the quantum state disturbs the system, alerting authorized users to the presence of an eavesdropper. This makes the communication fundamentally unbreakable, even if devices are compromised or imperfect.
Key advantages of entanglement-based QKD include:
- Enhanced Security: The quantum state disturbance caused by eavesdropping guarantees detection, ensuring the integrity of the distributed keys.
- Device-Independent Security: Unlike traditional methods, entanglement-based QKD remains secure even with imperfect or compromised devices.
- Scalability: This technology paves the way for long-distance QKD, quantum networks, and the envisioned quantum internet.
Quantum communication provides a dual-use technology with transformative applications in both civilian and defense sectors. Its fundamentally unbreakable encryption is critical for securing sensitive data in areas such as:
- Defense: Protecting national security-related communications and military operations.
- Finance: Safeguarding financial transactions and infrastructure against cyber threats.
- Telecommunications: Ensuring secure data transmission in an increasingly connected world.
The use of free-space QKD eliminates the need for costly and disruptive optical fiber infrastructure, making it particularly valuable in challenging terrains, dense urban environments, or remote areas. This flexibility enhances India’s ability to deploy secure communication networks rapidly and cost-effectively.
This achievement is part of India’s broader efforts to advance quantum technologies through the DRDO-Industry-Academia Centres of Excellence (DIA-CoEs). With 15 DIA-CoEs established at premier institutions like IITs, IISc, and other universities, DRDO is fostering collaboration to develop cutting-edge defense technologies. The free-space QKD project is a testament to the success of this initiative, combining academic expertise, industry innovation, and DRDO’s strategic vision.
Previous milestones include:
- 2022: Establishment of India’s first intercity quantum communication link between Vindhyachal and Prayagraj, utilizing underground dark optical fiber.
- 2024: Successful quantum key distribution over a 100 km telecom-grade optical fiber spool, demonstrating scalability for terrestrial networks.
These advancements align with India’s national objectives to harness quantum technologies for economic and strategic development, positioning the country as a key player in the global quantum race.
Raksha Mantri Shri Rajnath Singh congratulated DRDO and IIT Delhi, describing the achievement as a “landmark” that ushers India into a “new quantum era of secure communication.” He emphasized its potential as a “game changer in future warfare,” highlighting its strategic significance.
Secretary Department of Defence R&D and Chairman DRDO Dr Samir V Kamat, along with Director IIT Delhi Prof Rangan Banerjee, also lauded the team for their pioneering work. Their support underscores the collaborative spirit driving India’s quantum advancements.
The successful demonstration of free-space quantum secure communication opens the door to real-time applications in quantum cyber security. It lays the foundation for:
As India continues to invest in quantum technologies through initiatives like DIA-CoEs, the country is well-positioned to lead in quantum communication, enhancing national security and driving technological innovation.
India’s breakthrough in free-space quantum secure communication marks a defining moment in its technological journey. By achieving entanglement-assisted QKD over a kilometer-long free-space optical link, the DRDO-IIT Delhi collaboration has demonstrated the potential to transform secure communication for defense, finance, and telecommunications. With strong governmental support and a robust ecosystem of research and innovation, India is poised to play a pivotal role in shaping the future of quantum technology, ensuring a secure and connected world.