Defence Sector – DPP, Missions, Schemes, Security Forces, etc.

[pib] Quantum Key Distribution


From UPSC perspective, the following things are important :

Prelims level: QKD

Mains level: Secured Communications, QKD

A joint team of scientists from DRDO and IIT Delhi, for the first time in the country successfully demonstrated Quantum Key Distribution (QKD) link between Prayagraj and Vindhyachal in Uttar Pradesh, a distance of more than 100 kilometers.

What is QKD Technology?

  • Quantum key distribution (QKD) is a secure communication method that implements a cryptographic protocol involving components of quantum mechanics.
  • It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages.
  • It gives the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key.
  • This is a result of a fundamental aspect of quantum mechanics: the process of measuring a quantum system, in general, disturbs the system.
  • By using quantum superposition or quantum entanglement and transmitting information in quantum states, a communication system can be implemented that detects data leak.

How does it work?

  • QKD works by transmitting many light particles, or photons, over fiber optic cables between parties.
  • Each photon has a random quantum state, and collectively, the photons sent make up a stream of ones and zeros.
  • This stream of quantum states that make up ones and zeros are called qubits — the equivalent of bits in a binary system.
  • When a photon reaches its receiving end, it will travel through a beam splitter, which forces the photon to randomly take one path or another into a photon collector.
  • The receiver will then respond to the original sender with data regarding the sequence of the photons sent, and the sender will then compare that with the emitter, which would have sent each photon.

Benefits offered

  • It allows the detection of data leak or hacking because it can detect any such attempt.
  • It also allows the process of setting the error level between the intercepted data in dependence.


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