Re: Why does reading from /dev/urandom deplete entropy so much?

Marc Haber
2007-12-10T23:07:25Z

On Sun, Dec 09, 2007 at 10:16:05AM -0600, Matt Mackall wrote:
> On Sun, Dec 09, 2007 at 01:42:00PM +0100, Marc Haber wrote:
> > On Wed, Dec 05, 2007 at 03:26:47PM -0600, Matt Mackall wrote:
> > > The distinction between /dev/random and /dev/urandom boils down to one
> > > word: paranoia. If you are not paranoid enough to mistrust your
> > > network, then /dev/random IS NOT FOR YOU. Use /dev/urandom.
> >
> > But currently, people who use /dev/urandom to obtain low-quality
> > entropy do a DoS for the paranoid people.
>
> Not true, as I've already pointed out in this thread.

I must have missed this. Can you please explain again? For a layman it
looks like a paranoid application cannot read 500 Bytes from
/dev/random without blocking if some other application has previously
read 10 Kilobytes from /dev/urandom.

Greetings
Marc

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