[themenace]

If you want truly unbreakable encryption, there's always the one-time pad. In that case, the unbreakability is guaranteed by mathematics, an even stronger guarantee than physics.

Certainly, the one-time pad suffers from the need of each pair of parties to exchange keys beforehand. As far as I can see, the problem is just as bad for quantum crypto or this thermodynamic crypto because you have to arrange a fiber optic cable, a laser line of sight, or a copper wire between each pair who want to communicate.

You can't use quantum crypto or this thermodynamic crypto on the Internet for example. You need to set up unshared exclusive-use connections between each of the parties.

If you're going to the trouble of doing that, you might just as well exchange some terrabyte disks of one-time pad data, and you'll achieve the same (or greater) guarantee of security.

[yvdriess]

Quantum Cryptography is actually Quantum Key Distribution, an algorithm for securely creating a one-time pad between two peers. The proof that quantum crypto is unconditionally secure is just Shannon's proof.

The benefit of quantum crypto is that you can basically setup or even stream a one-time pad over a public network, without having to trust the middle-man. Another benefit over, say non-linear/chaotic systems is that fibre, line-of-sight wireless and satellite communication already forms the backbone of our network infrastructure.

Now only to solve the single-photon detector hardware issues.