News: As per the Indian Institute of Technology (IIT)-Delhi, India could be technologically capable of quantum communication using satellites in the next half a decade.
About Quantum Communication

- Quantum communication is a field of technology that uses the principles of quantum mechanics—especially the behavior of quantum particles like photons—to transmit information in a way that is fundamentally secure and resistant to eavesdropping.
- Key Features
- Quantum Key Distribution (QKD): The encryption keys are shared using quantum states (such as the polarization of photons).
- Any attempt to intercept or measure these quantum states disturbs them, revealing the presence of an eavesdropper.
- Quantum entanglement: Information can be transmitted using entangled particles, where the state of one instantly influences the state of another, no matter the distance.
- Unbreakable security: Because of the laws of quantum physics, quantum communication can provide theoretically unbreakable encryption.
- Quantum Key Distribution (QKD): The encryption keys are shared using quantum states (such as the polarization of photons).
- Under National Quantum Mission (NQM) of India, a strong focus is to develop satellite-based long distance quantum communication.
Quantum Communication Using Satellite
- A quantum satellite is a communications satellite leveraging the principles of quantum physics to secure data transmissions.
- Significance
- The emergence of quantum computers poses a threat to existing cryptographic systems.
- Quantum satellites aim to ensure secure communications by employing quantum cryptography particularly Quantum Key Distribution (QKD).
Demonstrations from across the globe
- China: In 2017 and 2020, researchers of China generated quantum keys involving a satellite (500 km above the ground) and ground stations 1,000 and 1,700-km apart.
- West: Since 2005, there have been ground demonstrations in Europe, Canada, and the United States of free-space (without cables) QKD greater than 100 km.
- India: In 2022, scientists from the Department of Space (DOS) demonstrated quantum entanglement based real time Quantum Key Distribution (QKD) over a 300-metre atmospheric channel.




