Transferring quantum data using single photons could be the key to total security. Now, researchers have developed a technique to generate very rapid light pulses of single photons that fits into current fiber optics systems.
The most promising encryption methods that should prevent attacks against computer systems rely on photons and their quantum properties.
Quantum cryptographers think entangled photons offer a priori inviolable security, and the viability of the concept has been successfully tested.
Using a quantum satellite, Micius, Chinese researchers encoded encryption keys and data on entangled photons.
Quantum Key Distribution technology is based on codes encrypted on photons that, being in an entangled state, allow the sender to immediately know if the data has been spied on or tampered with.
However, the problem scientists have been facing when dealing with single photons is that they can’t generate them fast enough to meet industrial needs.
Rapid Single Photon Pulses for Leakproof Security Systems
If quantum optics scientists could generate single photons, creating them at rapid rates remained problematic.
This is one of the issues limiting the potential of single photon based cryptography applications.
But physicists at the University of Sheffield (UK) may have found a way to overcome this hurdle.
“Using photons to transmit data enables us to use the fundamental laws of physics to guarantee security. It’s impossible to measure or ‘read’ the particle in any way without changing its properties. Interfering with it would therefore spoil the data and sound an alarm,” Said Mark Fox, Sheffield’s Professor of Optical Physics
Researchers are referring to the very rapid rates at which they could generate single photon pulses.
Basing their technique on a notion known as the Purcell Effect, researchers placed quantum dots inside cavities within a semiconducting crystal. The dots, when hit by laser beams, absorb it as energy and then re-emit it as single photons.
This Purcell Effect-based method allowed the team to generate single-photon pulses at a rate about 50 times faster than with other methods.
Sheffield researchers think they can achieve even faster rates. What’s more, at this emission rate, their technique, which enables them to create identical single photons, fits into the fiber optics industry.
“Our method also solves a problem that has puzzled scientists for about 20 years – how to use this Purcell Effect to speed up photon production in an efficient way,” said Fox. “This technology could be used within secure fibre optic telecoms systems, although it would be most useful initially in environments where security is paramount, including governments and national security headquarters.”