Quantum Key Distribution (QKD)

Context:

Recently, C-DOT and Sterlite Technologies Ltd. tested India’s first quantum key distribution over Multi-Core Fibre to boost secure, high-speed data transfer.

Relevance:
GS-03 (Science and technology)

What is Multi-Core Fibre (MCF) Technology:

MCF allows multiple optical signals to travel simultaneously through separate cores within a single optical fibre.
This becomes advantageous as it avoids the use of additional fibres being used for higher data transmission. This also reduces the burden on physical infrastructure.
This technique is very handy, especially in urban areas and data centres.
This technique also supports advancement in high-speed internet, cloud computing, and next-gen communication networks.

Quantum Key Distribution (QKD):

QKD is a revolutionary cybersecurity technique using principles of quantum mechanics to transmit encryption keys.
Uses photons (quantum particles of light) to encode the key. Any attempt to intercept the key alters the quantum state, thus alerting the users.
It offers unprecedented security as the key is known only to the sender and receiver — making eavesdropping virtually impossible.
Two Main Types of QKD:

Entanglement-based Protocols:

Pairs of entangled quantum particles are shared between two parties.
Any measurement on one instantly affects the other, ensuring the integrity of the key.

Prepare-and-Measure Protocols:

The sender prepares quantum states and sends them to the receiver, who measures them in specific bases to derive the key.

Benefits: Ultra-secure communication, especially useful in sensitive sectors like defence, banking, and critical infrastructure.
- It is capable of detecting intrusions in real-time.

Challenges:

High infrastructure costs due to specialized quantum hardware.
Needs dedicated fibre networks, limiting integration with existing systems.
Potential vulnerability to Denial-of-Service (DoS) attacks due to sensitivity of quantum states.

Prelims Practice Question:

Q. In the context of secure communications, the Quantum Key Distribution (QKD) technology works by:

A) Transmitting radio frequencies using encryption.

B) Transmitting quantum particles over optic cables to form encryption keys.

C) Converting sound waves into cryptographic messages.

D) Using satellite signals for message encryption.

Answer: B) Transmitting quantum particles over optic cables to form encryption keys.