Totally Secure Non-Quantum Communications?

An anonymous reader writes "TEES is reporting that Dr Laszlo Kish, an associate professor at Texas A&M, has proposed a 'classical, not quantum, encryption scheme that relies on classical physical properties -- current and voltage. He said his scheme is absolutely secure, fast, robust, inexpensive and maintenance-free and relies on simultaneous encrypting of information by both the sender and the receiver.' The scheme uses properties similar to Johnson noise along with Kirchoff's Law to provide what he hopes to be an easier method of secure communications. Arxiv also has the full text [PDF Warning] of the paper."

Comments

Credibility

[A beautiful mind]

"James Bond may use the fanciest, most expensive and high-tech devices to thwart would-be eavesdroppers, but in a pinch, the super-spy can use one Texas A&M engineer's simple, low-cost scheme to keep data secure from the bad guys."

This is the first sentence from the article. I'm sorry, but I cannot take anything in that article seriously. On another note the guy has an interestingly hungarian sounding name.

Too much hype

[KiloByte]

his scheme is absolutely secure, fast, robust, inexpensive and maintenance-free

Haven't we heard this before?
Generally, if something sounds too good to be true, it usually is neither good nor true.

Implementation

[GigsVT]

This sounds very good in theory, but it may be difficult to implement securely.

For example, he claims an eavesdropper could inject current to measure voltage drops, but would be discovered on the first attempt. If the eavesdropped can send a pulse of current that is so small as to not be registered on the endpoint equipment (which say samples the line at 1X sampling rate), but the attacker is injecting and sampling at a rate 100X faster, the attacker's pulse will be so far above the nyquist bandwidth of the endpoints that they will never see it.

I admit I only read the abstract, he may address this later on in the paper.

Why must non-cryptographers be so dumb?

[khaydarian]

There's so much wrong with this, I don't know where to start.

First, Cryptography is hard. Even professional cryptographers with decades of experience still get it wrong -- often. Considering as this guy has essentially no previous experience (he's an EE professor), it's already near certain that he's dead wrong.

Second, he doesn't provide "absolutely secure" communications. He provides non-interceptable communications. He's totally ignoring authentication, non-repudiation, man-in-the-middle attacks, and half a dozen other very important problems. (It's also not a cipher, but we'll ignore that slip.)

He also assumes (from the abstract) that an eavesdropper can only eavesdrop by injecting current into the wire, which is blatantly false. One could easily tap the magnetic field generated by current in the wire, without drawing very much power from the wire at all.

And to top it all off, he's depending on the precise values of voltage and current, which means this is an analog system. Analog systems are notoriously difficult to build precisely -- which is why we're using digital everywhere.

This is such bad research that I can't wait until Bruce Schneier get ahold of this.

Re:Outdated and irrelevant

[osu-neko]

Eh? Much like quantum communication systems, this is aimed at providing secure point-to-point communications. Almost everything you said above is utterly irrelevant to the question at hand. It doesn't solve any of the problems you bring up because it isn't meant to. Moving to hydrogen powered cars doesn't solve problems of secure Internet communcations, either. That doesn't make them a step backwards...

Re:Would this idea defeat the system?

[DrJimbo]

Eavesdropper wraps a wire around the communication wire, to measure the signal by induction. Would this be detectable? Or would this allow undetectable interception?

Yes, that would be detectable. For the same reason that we need a lot of falling water to turn the generators in hydro power plants. The energy (signal) in your wrapped wire does not come for free. It reduces the energy in the communication wire and is thus detectable.

Another way to see it: if the signal in your induction pickup were truly undetectable then we could wrap billions of similar induction pickups around the communications wire and generate electricity "too cheap to meter".