alt.lawyers

Cynic wrote in
news:dqrcg31e9dg0f5bq7g9b76l6o34k5ntpi2@ :

> On Fri, 05 Oct 2007 16:54:32 GMT, bealoid
> wrote:
>
>>>>Because "random" is tricky to define.
>
>>> You will find that it has been defined pretty precisely.
>
>>"Is 2 random?"
>
> Like statistics, such a determination (in the context under
> discussion) cannot be made from a single sample.

You don't recognise the quote?

[snip]

> It will not. I do this stuff for a living, and have studied it
> extensively.

You do what stuff for a living, and what have you studied extensively?
I'm guessing it's not crypto, but I could be wrong.

I've seen many implementations of hardware RNGs, and they're usable for
small amounts of random data. They're not usable for large amounts of
cryptographically useful random data.

Webcams and lavalamps are fun weak RNGs, but you don't need the lavalamp.
Webcams generate enough noise if you block the lens with dark card.

[snip]

> In any case, the fault described resulted in a bias in the 0's and
> 1's, which should be almost equal in a large enough sample.

0s and 1s should be almost equal in a large enough sample of random data.
A bias would mean more of one than the other. So, I'm having trouble
understanding your sentence.

> The hardware generators described must be either old devices or units
> built by someone who doesn't know what they are doing.

And yet they were on sale, by people who claimed to know what they were
doing, to people who claimed to know what they're doing.

> All generators
> that I have seen has the noise fed through a toggle (divide by two)
> which ensures that there cannot possibly be a bias between 0's and 1's
> no matter how assymetric the noise signal is.

von Neuman's method kills bias but not correlation. All kinds of stuff
can introduce bias and correlation in electrical noise generators-
different temperature, voltage drifts, etc.

Thus, the signal isn't -cryptographically- really random, and is open to
attack.