[cryptography] Duplicate primes in lots of RSA moduli

Thierry Moreau thierry.moreau at connotech.com
Fri Feb 17 15:39:44 EST 2012

Ben Laurie wrote:
> On Fri, Feb 17, 2012 at 7:32 PM, Thierry Moreau
> <thierry.moreau at connotech.com> wrote:
>> Isn't /dev/urandom BY DEFINITION of limited true entropy?
> $ ls -l /dev/urandom
> lrwxr-xr-x  1 root  wheel  6 Nov 20 18:49 /dev/urandom -> random

The above is the specific instance on your environment. Mine is 
different: different kernel major/minor device numbers for /dev/urandom 
and /dev/random.

I got the definition from

man 4 random

If your /dev/urandom never blocks the requesting task irrespective of 
the random bytes usage, then maybe your /dev/random is not as secure as 
it might be (unless you have an high speed entropy source, but what is 
"high speed" in this context?)

- Thierry Moreau

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