Using spatial coded light in Quantum Key Distribution

Sending light with large alphabet encoding. Credit: University of Twente

Researchers of the University of Twente found a new way to protect data from attacks using quantum computers. Single particles of light in Standard Quantum Key Distribution (QKD) systems are already being used to protect data but the transmission of one bit per photon is slow.

The team aims to increase the transmission speed up to seven bits per photon, reaching the equivalence of more than a thousand letters. This increases the resistance against noise and potentially increases the data rate. They achieved this by encoding the quantum information in 1024 possible locations of the used photons. To make it hard for an attacker to see what was sent, they randomly switch the encoding between two different alphabets.

Their results are published on December 18th in New Journal of Physics in their paper titled “Large-alphabet quantum key distribution using spatially encoded light.” (University of Twente)

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