lkml.org 
[lkml]   [2012]   [Oct]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: urandom is too slow
On Tue, Oct 30, 2012 at 04:55:22PM +0200, Lasse Kärkkäinen wrote:
> Apparently there has been little or no development on urandom even
> though the device is in widespread use for disk shredding and such
> use. The device emits data at rather slow rate of 19 MB/s even on
> modern hardware where other software-based PRNGs could do far
> better. An even better option seems to be utilizing AES for
> encrypting zeroes, using a random key, allowing for rates up to 500
> MB/s with hardware that has AES-NI instructions.
>
> Why is urandom so slow and why isn't AES hardware acceleration utilized?

If you can use a software-based PRNG, you should use one in userspace.
The intended use of urandom is for cryptographic purposes (i.e.,
generating random session keys, long-term public keys, etc.). If you
just want to wipe a disk, you shouldn't be using /dev/urandom for that
purpose.

Regards,

- Ted
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2012-10-31 08:21    [W:0.060 / U:0.344 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site