[Cryptography] who cares about actual randomness?

[Erwan Legrand]

On Wed, Feb 5, 2014 at 10:11 AM, John Denker <jsd at av8n.com> wrote:
> In the context of /dev/random versus /dev/urandom,
> on 02/04/2014 11:48 PM, ianG wrote:
>
>> It was a hard lesson to learn I think.  I recall being quite angry when
>> FreeBSD tied them together, for years even.
>>
>> Now that hindsight is possible, one can look at the results.  Did
>> FreeBSD ever find an application that had a genuine need for entropy
>> rather than unguessable numbers?
>
> How about you and me get together for a nice friendly
> game of poker.
>
> I'll bring the cards.  I'll bring several decks, so we can
> use a fresh deck for each hand.  This saves time, because
> they're already shuffled, using my favorite PRNG.  The PRNG
> is strong enough to make it computationally infeasible for
> you to find any non-random pattern in the cards.


The issue lies in the protocol you suggest. Let's use Blum's coin
flipping by telephone to generate a non-random stream of bits that
neither you nor I can predict.

Erwan