Field Demonstration of a Multiple Trusted Node Quantum Key Distribution on an Electric Utility Fiber Network*

Quantum Key Distribution (QKD) provides a unique solution for the distribution of secret keys used for information authentication and encryption. QKD has the potential to yield several benefits including protecting critical energy delivery infrastructure which needs long-term authentication and encryption solutions. A real-world scenario for the practical use of this technology can be applied to the distribution of network keys between the operations center and electrical substations. We successfully demonstrated a trusted-node QKD network comprised of three diverse QKD systems working autonomously on an electric grid and collected data over a period of 28 hours. The interoperability of these devices extends the physical distance for which they can distribute secret keys, covering larger territory than a single system operating on its own. The network demonstrated the generation of quantum secret keys between the operations center and several electrical utility substations. This was the world’s first demonstration relaying secret keys between energy delivery infrastructure.