Have you heard about the new cheesy ad campaign to get funding for quantum research? It’s called Quantum Encryption or Quantum Cryptography. Sure, QE and QKD (Quantum Key Distribution) have been around in the form of a high budget grade school science project for years, but only recently has it become a major marketing campaign for Quantum Everything.
Sure, better encryption is interesting, actually it isn’t, but it’s more interesting than worse encryption. So, being the closest to practical branch of the quantum yawn-fest, it is most likely to gain acceptance in the target demo; people who have money and want to keep secrets. This conveniently includes many world governments which actually have a “license” to print money.
So what is QE? It is the simplest, most linear, most pedantic, most restricted, least quantumy branch of supposed quantum application. It is essentially based on moving a photon from one place to another. The idea is that if you look at it, it is altered, if it is altered there is a warning, if there is a warning encryption can be changed, if encryption is changed it naturally follows that data is protected.
Ideally your quantum key consisting of photons would contain no duplicates, if there were duplicates, then someone could eavesdrop and take all your data. This is where it is demonstrated that viewing a thing changes that thing. Now, when dealing with entanglement and other things (that we may never need to deal with), this is a slightly less dull concept, but when dealing with QE is it really that complicated? You’ve already done the math...
Sure, viewing a single photon changes a photon. You get the photon. If Janie has an apple (in a bag) and she gives you an apple (in a bag) then you have an apple to look at, and the apple is no longer in its (recent) state of unlimited possibility. It follows that if that apple was intercepted by Jimmy and you see Janie walking toward you with an empty bag, you will change your apple delivery system or start using theft-resistant apples. That’s a practical application of QE.
Unfortunately, QE has not reached this level yet because Janie often produces identical apples, one of which can easily be intercepted by Jimmy without you knowing. The state of apple clone #1 was not changed from its intended course, and the state of apple #2 was never an issue. Now Jimmy can sit and stare at all your duplicate apples and really get to know them.
What is the solution? QE recommends a stopgap: Produce multiple dummy apples to confuse Jimmy. As he reaches out to grab Janie’s (seemingly) randomly thrown apples he can’t be absolutely sure that he’s getting a duplicate apple or a randomly generated apple. We are only a few years away from implementation of this technology.
I’m not saying any of this to deny the validity of Quantum Anything, I admire the use of addition and subtraction by these great scientists.
Quantum cryptography is often referred to as consisting of *both* classical and quantum techniques. If some of the researchers developing this “science” are implementing any quantum techniques, I don’t see why, because they don’t need to in order to carry this label. In fact, if they continue to rely on classical physics as they do now, it will make it to market sooner, they will get more brand recognition, the sheep will believe that it is really quantum science. Of course, they could just put out the Quantum Toaster and claim that it incorporates mysteries of string theory to get your toast done perfectly ... until looking at it changes it. It will be a big hit!