CONTEXT

• Quantum communication is an emerging technology crucial for secure data transmission.
• It uses Quantum Key Distribution (QKD) to exchange encryption keys based on quantum mechanics.
• India is currently in the experimental stage of developing this capability.
• China has already demonstrated satellite-based quantum communication as early as 2017 and 2020.
• India aims to achieve satellite-based quantum communication by 2030, according to IIT-Delhi.

CONCEPT

• Quantum Key Distribution (QKD) enables ultra-secure key exchange using photons.
• Based on quantum entanglement, where a change in one photon affects its pair instantaneously.
• Key feature: Any interception attempt is detectable, ensuring communication integrity.
• Two main approaches to QKD:
  • Fibre-based QKD: stable but costly over long distances.
  • Free-space QKD: wireless, scalable via satellites but technically complex.
• Atmospheric disturbances (turbulence, pollution, etc.) degrade free-space QKD accuracy.
• Satellite-based QKD overcomes distance limits and allows global coverage.
• The technology demands interdisciplinary collaboration and advanced optics.

CURRENT STATUS (INDIA)

• IIT-Delhi demonstrated QKD over 1 km in free-space, India’s farthest attempt without cables.
• The project is at proof-of-concept (POC) level with a small research team.
• High error rates still exist due to beam divergence and environmental noise.
• Optimisation in beam control and error correction techniques is ongoing.
• Transition to satellite-based quantum communication will need:
  • Large-scale funding
  • Dedicated start-ups
  • Skilled multi-disciplinary teams
• Target: Achieve full satellite-based quantum communication capability by 2030.

MAINS QUESTION

1. What are the implications of quantum communication technology for secure data transmission, and how can it be used to protect sensitive information?
2. How can India leverage its current research and development in QKD to achieve a leadership position in quantum communication technology?