Key quantum-based technology developed to ensure secure strategic communications
Technology developed under the aegis of Defence Research and Development Organisation (DRDO) has paved way for development in quantum cyber security, quantum networks and future quantum internet, making India’s entry into a new era of secure communications that will be a game changer in future warfare.
DRDO, in collaboration with the Indian Institute of Technology on Monday demonstrated “Quantum Entanglement-Based Free-Space Quantum Secure Communication” over a distance of more than 1 km. This was achieved via a free-space optical link established on the IIT campus.
Quantum communication provides fundamentally unbreakable encryption, making it a dual-use technology with applications in securing data in strategic sectors such as defence, finance and telecommunications, as well as in protecting national security-related communications. Free-space QKD eliminates the need to lay optical fibres, which can be both disruptive and expensive, especially in challenging terrains and dense urban environments.
The experiment attained a secure key rate of nearly 240 bits per second with a quantum bit error rate of less than seven per cent. This entanglement-assisted quantum secure communication paves the way for real-time applications in quantum cyber security, including long-distance Quantum Key Distribution (QKD), the development of quantum networks, and the future quantum internet.
Under the project ‘Design and development of photonic technologies for free space QKD’, sanctioned by DRDO’s Directorate of Futuristic Technology Management (DFTM), the demonstration was conducted by Prof Bhaskar Kanseri’s research group in the presence of several senior scientists from different DRDO establishments and IIT.
Quantum based cyber and information security is based on quantum mechanics, a fundamental theory in physics that explains the behaviour of matter and energy at the atomic and subatomic levels.
Quantum entanglement-based QKD offers several significant advantages over the traditional ‘prepare-and-measure’ method by enhancing both security and functionality. Even if devices are compromised or imperfect, the use of quantum entanglement ensures the security of key distribution. Any attempt to measure or intercept the entangled photons disturbs the quantum state, allowing authorised users to detect the presence of an eavesdropper.
Earlier, India’s first intercity quantum communication link between Vindhyachal and Prayagraj in 2022, using commercial-grade underground dark optical fibre was demonstrated by DRDO scientists along with Prof Bhaskar’s team.
More recently, in 2024, the team successfully distributed quantum keys using entanglement over a 100 km spool of telecom-grade optical fibre in another DRDO-supported project.
These technologies are being developed through the DRDO-Industry-Academia – Centres of Excellence (DIA-CoEs) – an initiative of DRDO, where 15 CoEs have been established at premier academic institutes like IITs, Indian Institute of Science and various universities for development of cutting edge defence technologies.
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