In a major scientific breakthrough, India has successfully demonstrated a cutting-edge advancement in quantum communication, marking a significant leap toward secure real-time applications in quantum cybersecurity. This milestone was achieved through a collaborative effort between the Defence Research and Development Organisation (DRDO) and the Indian Institute of Technology (IIT) Delhi.
The Defence Ministry, in an official statement on Monday, announced that scientists had established a free-space quantum communication link using quantum entanglement across a distance of over one kilometre on the IIT-Delhi campus. This achievement, made possible through a free-space optical link, signifies the beginning of what officials describe as India’s “new quantum era.”
Defence Minister Rajnath Singh congratulated the team, stating that the development represents a “game-changer” in future warfare capabilities, particularly in secure communications. “India’s entry into the new quantum era highlights our growing technological prowess in strategic domains,” he noted.
The demonstrated system used entanglement-assisted Quantum Key Distribution (QKD), a method that offers heightened security compared to conventional approaches. Unlike traditional key-sharing mechanisms, entanglement-based QKD ensures that any attempt to intercept the data disrupts the quantum state, alerting users to potential breaches. The experimental setup achieved a secure key rate of around 240 bits per second, with a quantum bit error rate below 7%.
This experiment is part of the DRDO-funded project titled “Design and Development of Photonic Technologies for Free Space QKD,” carried out by Prof. Bhaskar Kanseri’s research group. The demonstration was witnessed by senior DRDO officials, IIT Delhi’s Dean (R&D), and scientists from the DRDO laboratories.
Quantum communication technologies, which provide virtually unbreakable encryption, are increasingly viewed as crucial for safeguarding sensitive data in areas like defence, finance, and national security. The ability to transmit encrypted data through free space — without relying on traditional fiber optic infrastructure — also offers a strategic advantage in rugged and urban terrains.
India’s efforts in this field are not new. In 2022, DRDO and IIT-Delhi had successfully demonstrated the country’s first intercity quantum communication link between Vindhyachal and Prayagraj using underground dark fiber. More recently, in 2024, the same research team achieved quantum key distribution over a 100 km stretch of telecom-grade optical fiber.
These initiatives are being developed under the DRDO-Industry-Academia Centres of Excellence (DIA-CoEs), established across 15 premier academic institutions, including several IITs and the Indian Institute of Science (IISc). The aim is to foster innovation in advanced defence technologies.
DRDO Chairman and Secretary of the Department of Defence R&D, Dr. Samir V. Kamat, and IIT Delhi Director, Prof. Rangan Banerjee, both lauded the team for their pioneering work, underlining the strategic importance of this achievement in India’s defence and technological roadmap.