[graylights]

What's involved in the handling of this glass? They claim security because heating the glass damages its structure. A fingerprint or scratch would also damage it. Is it secure because it's just so fragile that it is plain unworkable in real world conditions?

Also this article doesn't touch on whether the randomness generated is sufficiently random for cryptographic purposes. With enough error correction and an improper random distribution, it can become possible to break even OTP.

[ReidZB]

I'm not sure about the handling of the glass. The paper [1] gives all of the specific materials used in the experiment, but it doesn't say anything about handling them and I don't know enough about the area to be able to intelligently comment...

The paper also mentions that the randomness they are using passes the Diehard and NIST randomness tests, so it appears they are pretty random. Apparently, though, they have to sacrifice some of the bits in order to ensure that! It references "Supplements" E and F, saying they include more details, but they're not included in the arXiv paper. Of course, the original random patterns used to generate the keys are randomly selected too, so let's hope they're using a good random source for that...

[1]: http://arxiv.org/abs/1305.3886