Questions about reliability...

[Robert Lee]

The term "breakdown" is a reference to breakdown voltage. Breakdown
voltage is simply the point where a semiconductor is pushed past its
ability to resist an electrical current demanding to go in the "wrong
direction" (i.e. reverse bias).

Now whether this breakdown will cause the semiconductor itself to fail
depends on the semiconductor. Some semiconductors such as zener diodes
are perfectly happy to go both ways: in normal bias electricity flows
freely, in reverse bias electrical current is halted until breakdown
voltage is reached.

At near breakdown voltage (the point at which the electrical dam is
about to bust) the semiconductor becomes electrically noisy. That noise
is wonderful for this application as it is a result of quantum action
(excellent, physical, truly non-deterministic stuff you can feel in your
bones!).


> 1. If they're being kept "near to breakdown", does this mean they have a significant failure rate? What's the MTBF of these keys? (That's how I read this page as a software engineer! I understand cryptography and entropy generation, but not electronics. If this isn't how it should be read, then I'd urge a note to that page!)