As the world becomes more dependent on computers to simplify tasks in our daily lives, the nation's energy grid is no exception. Computers have made renewable energy possible, and they constantly monitor our power consumption and redirect energy, allowing us to decrease our collective carbon footprint.

As we know, with technology comes great advances. But it can also open pathways into these energy systems for those who want to cause harm. Bad actors are constantly searching for ways to circumvent the safeguards designed to protect our computer-dependent world. Whether that's stealing credit card information, or an adversary secretly entering the nation's power grids, designing methods to stop these people is a national security concern.

This is why sensitive information sent through computers is encrypted. And when it comes to something as vital as the electrical grid, scientists in the field of cryptography develop highly complex, mathematically based security codes to protect this information.

These computer codes are virtually uncrackable, and it's a credit to cryptographers that the nation's grid has remained so secure. But as computing power steadily increases, cryptographers and the people hoping to infiltrate these systems are in a constant race that has become increasingly harder for those protecting the grid to win.

Rather than running this race by developing more and more complex codes, for the past eight years Los Alamos National Laboratory has developed a new method for protecting information sent through the nation's grid system called Quantum Ensured Defense (QED). Instead of math, this method is based on immutable laws of physics and uses single particles of light, or photons, to protect information.

Raymond Newell is a scientist at Los Alamos National Laboratory.
Raymond Newell is a scientist at Los Alamos National Laboratory.

To gain access to something such as a power station, our adversaries need to surreptitiously enter its computer system, intercept and copy the encryption code, then set about unraveling it. Keeping intruders out of the grid system is difficult because it can be hard to know if someone has entered it in the first place. So instead of focusing on locking eavesdroppers out, QED makes it impossible for them to secretly view the signals used to control power generation, transmission, and distribution.

Already, photons transmit information through fiber optic cables, the hair-sized strands of glass that are often wound into the black rolls of wire strung on utility poles. Much of the information sent through the internet is done this way, passed through the fiber optic wires as pulses of photons from a transmitter on one end to a receiver at the other.

QED uses these same principles. Quantum transmitter and receiver devices, designed at Los Alamos, are placed in power plants or substations to establish secure links. They encode information onto individual photons at the transmitter, send the photons over optical fibers, then detect the photons and recover the information at the receiver. We know the information is protected for three reasons: a photon cannot be cut in half; a photon cannot be accurately copied; and a photon cannot even be measured without changing it in some way.

These three properties are fundamental to quantum physics—they are "baked in" to the way our universe works. As a consequence, no eavesdropper can keep a fraction of the secret, or make a copy of the secret, or even look at the secret without revealing that they have looked. The result is an unhackable method for sending information between generators, substations, and into homes.

In the future, this same technology could also be applied to other industries that need protection, whether that's bank transfers, protecting government information, or sensitive hospital records.

Unfortunately, cybercrime will always exist. As long as there is sensitive information to steal, someone will try to steal it. That's why it's vital to the safety of the nation and the economy that we have a secure means of keeping this data out of the wrong hands. A single particle of light could be the answer.

Raymond Newell is a scientist at Los Alamos National Laboratory.