Quantum Key Distribution

What Does Quantum Key Distribution Mean?

Quantum key distribution (QKD) is the use of laser beams to transmit cryptographic keys securely using the quantum properties of photons in laser beams. The photons are coded in binary ones and zeroes which are then picked up by the receiving equipment. This makes it possible to transmit keys without them being intercepted.


Techopedia Explains Quantum Key Distribution

Quantum key distribution exploits quantum mechanics to transmit keys between two parties securely. While a key, or a one-time pad, is theoretically unbreakable, the key challenge is getting both parties in a conversation to agree to the same key without the key being intercepted by a third party.

Quantum key distribution uses lasers to transmit the keys. The quantum properties of photons in the beams are coded into binary ones and zeroes. While a third party can intercept the beam, by being observed, the quantum properties change, making the keys useless to an attacker.

A practical application of the technique is secure communication between submarines. Commercial QKD systems are aimed at those with a need for high security, such as the defense industry.


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Margaret Rouse
Technology Expert

Margaret is an award-winning technical writer and teacher known for her ability to explain complex technical subjects to a non-technical business audience. Over the past twenty years, her IT definitions have been published by Que in an encyclopedia of technology terms and cited in articles by the New York Times, Time Magazine, USA Today, ZDNet, PC Magazine, and Discovery Magazine. She joined Techopedia in 2011. Margaret's idea of a fun day is helping IT and business professionals learn to speak each other’s highly specialized languages.