The future of communication has one very important need in common with the
communication of the past and that's the need to keep it safe from prying eyes and ears.
It's why the ancient Greeks had their whispers. It's what inspired the
Enigma machine of World War II, and today, digital encryption.
All of these however could be compromised. The problem is when someone listens in
on secret communication, or copies sensitive data, it can be impossible to tell.
But today's engineers working on communication systems of tomorrow have a plan to change that.
They call it "secure quantum communication".
In quantum physics, which is the established science that underpins all matter in our universe
there are unique particles called entangled photons and they share a
quantum state with each other.
These tiny elements of energy are generated in pairs.
What's amazing about entangled photons is that disturbing or altering
one of them also alters the other. Theoretically even when they're miles
and miles apart, scientists and engineers are working on an exciting application
for this that could make the future of communication hack proof and eavesdrop proof.
In current systems information is sent through cables and airwaves and if
someone listens in on it there's no surefire way to know it.
That's because eavesdropping on a typical data transmission doesn't affect
the data itself, it can still arrive and its destination nobody the wiser.
Now let's take another look at those entangled photons, remember that if one
is disturbed or changed the other is also changed no matter how far apart the two of them are.
The sender creates a pair of entangled photons from a generator.
She keeps the first one and sends the other one down the line on its way to the final receiver.
Now if that message is intercepted and listened to that very impact on the second photon changes the
first photon. Since the two photons mirror each other the sender knows the
line isn't secure so she won't send the sensitive data.
But if the photon arrives at the detector down the line untouched she knows the data is safe, at that point
another generator creates a new pair of entangled photons and the process starts again.
This chain of "qubit" transmitters, repeaters and receivers when strung together can establish secure
communication that could potentially reach anywhere in the world.
The word photon comes from the distant past. It's inspired by the ancient Greek word for light.
But today these tiny entangled particles are allowing engineers to
create communication networks of the future that will be the best secret keepers yet.