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Date: Fri, 20 Apr 2012 18:55:53 +0800
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From: Rodel Miguel <rodelfmiguel@gmail.com>
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Subject: Re: [dm-crypt] why nbytes for block cipher encrypt/decrypt is only
 512 bytes
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Hi Arno , thanks for the reply. What if I trick the system to have block
size of say 128 instead of the default 16 for my AES driver? Do you know
what the side effect could be?

Thanks!
On Apr 20, 2012 6:23 PM, "Arno Wagner" <arno@wagner.name> wrote:

> I think you cannot. As long as the block-size for the IV scheme
> is 512 bytes, you are stuck with encrypting 512 bytes at a time,
> as they have their own IV.
>
> Arno
>
>
> On Fri, Apr 20, 2012 at 05:28:54PM +0800, Rodel Miguel wrote:
> > Hi,
> >
> > I am implementing a hardware encryption driver but I am having some
> > performance issues.  One of the areas of performance improvement that I
> am
> > thinking is to increase the number of bytes (unsigned int nbytes) that my
> > block cipher driver's encrypt/decrypt function gets; from 512 to 4096
> > bytes.  My hardware can be maximized to 4kbytes.  Do you have any
> > suggestions how I can maximize the en/decrypt performance by getting more
> > than 512 bytes of data every time the block cipher's encrypt/decrypt is
> > called?
> >
> > Thank you very much for your help!
> >
> > Kind Regards,
> > Rodel
>
> > _______________________________________________
> > dm-crypt mailing list
> > dm-crypt@saout.de
> > http://www.saout.de/mailman/listinfo/dm-crypt
>
>
> --
> Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email:
> arno@wagner.name
> GnuPG:  ID: 1E25338F  FP: 0C30 5782 9D93 F785 E79C  0296 797F 6B50 1E25
> 338F
> ----
> One of the painful things about our time is that those who feel certainty
> are stupid, and those with any imagination and understanding are filled
> with doubt and indecision. -- Bertrand Russell
> _______________________________________________
> dm-crypt mailing list
> dm-crypt@saout.de
> http://www.saout.de/mailman/listinfo/dm-crypt
>

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<p>Hi Arno , thanks for the reply. What if I trick the system to have block=
 size of say 128 instead of the default 16 for my AES driver? Do you know w=
hat the side effect could be?</p>
<p>Thanks!</p>
<div class=3D"gmail_quote">On Apr 20, 2012 6:23 PM, &quot;Arno Wagner&quot;=
 &lt;<a href=3D"mailto:arno@wagner.name">arno@wagner.name</a>&gt; wrote:<br=
 type=3D"attribution"><blockquote class=3D"gmail_quote" style=3D"margin:0 0=
 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
I think you cannot. As long as the block-size for the IV scheme<br>
is 512 bytes, you are stuck with encrypting 512 bytes at a time,<br>
as they have their own IV.<br>
<br>
Arno<br>
<br>
<br>
On Fri, Apr 20, 2012 at 05:28:54PM +0800, Rodel Miguel wrote:<br>
&gt; Hi,<br>
&gt;<br>
&gt; I am implementing a hardware encryption driver but I am having some<br=
>
&gt; performance issues. =A0One of the areas of performance improvement tha=
t I am<br>
&gt; thinking is to increase the number of bytes (unsigned int nbytes) that=
 my<br>
&gt; block cipher driver&#39;s encrypt/decrypt function gets; from 512 to 4=
096<br>
&gt; bytes. =A0My hardware can be maximized to 4kbytes. =A0Do you have any<=
br>
&gt; suggestions how I can maximize the en/decrypt performance by getting m=
ore<br>
&gt; than 512 bytes of data every time the block cipher&#39;s encrypt/decry=
pt is<br>
&gt; called?<br>
&gt;<br>
&gt; Thank you very much for your help!<br>
&gt;<br>
&gt; Kind Regards,<br>
&gt; Rodel<br>
<br>
&gt; _______________________________________________<br>
&gt; dm-crypt mailing list<br>
&gt; <a href=3D"mailto:dm-crypt@saout.de">dm-crypt@saout.de</a><br>
&gt; <a href=3D"http://www.saout.de/mailman/listinfo/dm-crypt" target=3D"_b=
lank">http://www.saout.de/mailman/listinfo/dm-crypt</a><br>
<br>
<br>
--<br>
Arno Wagner, Dr. sc. techn., Dipl. Inform., CISSP -- Email: <a href=3D"mail=
to:arno@wagner.name">arno@wagner.name</a><br>
GnuPG: =A0ID: 1E25338F =A0FP: 0C30 5782 9D93 F785 E79C =A00296 797F 6B50 1E=
25 338F<br>
----<br>
One of the painful things about our time is that those who feel certainty<b=
r>
are stupid, and those with any imagination and understanding are filled<br>
with doubt and indecision. -- Bertrand Russell<br>
_______________________________________________<br>
dm-crypt mailing list<br>
<a href=3D"mailto:dm-crypt@saout.de">dm-crypt@saout.de</a><br>
<a href=3D"http://www.saout.de/mailman/listinfo/dm-crypt" target=3D"_blank"=
>http://www.saout.de/mailman/listinfo/dm-crypt</a><br>
</blockquote></div>

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