Brief Context
Context India has successfully demonstrated quantum secure communication using quantum entanglement over free space by the DRDO-Industry-Academia Centre of Excellence (DIA-CoE), IIT Delhi. Quantum Communication Quantum communication uses quantum physics, especially quantum entanglement, to create ultra-secure channels for sending information. Quantum Entanglement: When two photons are entangled, measuring one instantly determines the state of the other — even if they are far apart.
Source Content
Syllabus: GS3/Science and Technology
Context
- India has successfully demonstrated quantum secure communication using quantum entanglement over free space by the DRDO-Industry-Academia Centre of Excellence (DIA-CoE), IIT Delhi.
- This marks a significant milestone in India’s quantum technology roadmap.
Key Highlights
- Technology Used: Quantum Entanglement-based Free-Space Quantum Key Distribution (QKD).
- Secure Key Rate: ~240 bits per second.
- Quantum Bit Error Rate (QBER): < 7%.
- Distance: Over 1 km free-space optical link on IIT Delhi campus.
Quantum Communication
- Quantum communication uses quantum physics, especially quantum entanglement, to create ultra-secure channels for sending information.
- Quantum Entanglement: When two photons are entangled, measuring one instantly determines the state of the other — even if they are far apart.
- Main purpose: To make communication leak-proof. Any eavesdropping attempt will disturb the entangled state, revealing the intrusion.
What is Quantum Key Distribution (QKD)?
- QKD allows secure exchange of encryption keys using quantum mechanics.
- Uses photons (light particles) as information carriers.
- Quantum entanglement-based QKD is highly secure — any hacking attempt disturbs the system and gets detected.
- Entanglement-based Quantum Key Distribution (QKD) Advantages:
- Security even with imperfect or compromised devices.
- Intrusion detection through quantum state disturbance.
- More robust than traditional prepare-and-measure QKD methods.
- Applications:
- Defence communications.
- Secure banking and telecom networks.
- Strategic sector data protection.
- Cost-effective: Free-space QKD avoids costly fiber-laying in challenging geographies.
Why Free-Space Communication?
- Free-space or satellite-based QKD can connect long distances without laying cables.
- Cables (optical fiber) become costly and impractical over long distances.
Global Comparison
- China is leading with a 4,600 km quantum network since 2021.
- China had demonstrated satellite-based quantum communication nearly one decade ago, as they had a head start in quantum communication activities since the early 2000s.
- Since 2005, there have been ground demonstrations in Europe, Canada, and the United States of free-space (without cables) QKD greater than 100 km, suggesting that India still has much to cover regarding QKD-entanglement communication.
Challenges
- It requires not only adequate funds but also a large, dedicated team of multidisciplinary skilled experts for developing several types of enabling technologies.
- Atmospheric disturbances increase error in free-space.
- India started late (2020s) and must catch up with global leaders.
- Using fibre optic cables provides a stable channel for quantum communication which free-space channels do not.
Future Plans
- Under the National Quantum Mission (NQM) India is focusing on satellite-based long-distance QKD.
- The support includes quantum start-ups, indigenous equipment, and lab-to-market technologies.
- India aims to achieve satellite-based QKD and a quantum network across India in 5–10 years.
Source: TH