[Cryptography] Entropy of a diode

[John Denker]

On 07/20/2016 02:17 PM, Kurt Roeckx wrote:
> I'm trying to understand the entropy generated by a reversed diode
> in avalanche breakdown mode.  Does anybody know of a paper that
> describes it, maybe talk about the distribution of the noise, the
> effect of temperature changes, RF interference?
> 
> I'm trying to analyze the chaoskey.

Background remark: noise in a Zener diode is basically shot noise.

Meanwhile, noise in an avalanche diode is basically shot noise,
amplified by (you guessed it) the avalanche effect.

Most importantly, if you pull random diodes off the shelf, you
have no idea what noise you're going to get, because they're not
designed for that. The manufacturer could "improve" the process
tomorrow in a way that reduces the noise. If you look at a typical
spec sheet, it doesn't mention noise at all:
http://www.vishay.com/docs/88958/byg20d.pdf

OTOH if you are talking about a diode intended and optimized for
use as a noise source, you have to look at the spec sheet for
that particular diode.

Any book on semiconductor physics will talk about the avalanche
effect. Any book on low-noise circuit design will talk about
shot noise. I get 10,000 hits from
https://scholar.google.com/scholar?q="shot+noise"+avalanche

If that's not good enough, please ask a more specific question.