[cryptography] urandom vs random

shawn wilson ag4ve.us at gmail.com
Fri Aug 16 22:33:11 EDT 2013


On Fri, Aug 16, 2013 at 10:01 PM, James A. Donald <jamesd at echeque.com> wrote:
> At startup, likely to be short of entropy.
>

> If /dev/urandom seeded at startup, and then seeded no further, bad, but not
> very bad.
>
> If /dev/urandom seeded at startup from /dev/random, then should block at
> startup.
>
> If /dev/urandom never blocks, bad.  Should block at startup waiting to
> receive 160 bits from /dev/random, and never block again.
>

I don't follow this - I understand why lack of entropy should block
urandom but, why shouldn't it block on a running system that
<low_bound?


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