Current protocols such as quantum key distribution, a prevailing approach in cybersecurity research, are designed for only two parties and, in one instance, uses a pair of light particles called entangled photons. Securely extending quantum cryptography to three parties usually requires the difficult step of creating a three-photon entangled state.
"In our experiment, we were able to add the laser source as a third active participant while only needing to produce one pair of photons", stated ORNL's Brian Williams, lead author of the study published in Physical Review A . "Our method removes the need for producing a third photon, which dramatically improves operation efficiency."
This finding could inspire improved security for existing and future computer networks.