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Re: [iaik-jce] DES - Implementation of IAIK and IV



Yes, we discovered this difference recently. However, it was not fixed
for compatibility with previous versions and because it is generally not
a good idea to use IVs or secret keys more than once anyway. It has not
been decided how we will handle this in the future.

 Andreas Sterbenz              mailto:Andreas.Sterbenz@iaik.at


-----Ursprüngliche Nachricht-----
Von: <wplaner@eunet.at>
An: <iaik-jce@iaik.tu-graz.ac.at>
Gesendet: Mittwoch, 25. Oktober 2000 15:43
Betreff: [iaik-jce] DES - Implementation of IAIK and IV


> There is a little difference between  IAIK and  Sun in the
Implementation of DES
> in CBC - Mode:
> - after a doFinal () Sun resets the IV to the value set in engineInit
> - IAIK reuses the actual value of the IV
>
> The difference becomes a problem when one single cipher - object is
used to
> encrypt multiple blocks of data in
> CBC - mode with the same initial IV
>
> A simple but not efficient workaround is to subclass
iaik.security.cipher.DES
> and to keep track of the parameters
> used in engineInit. A separate boolean instance variable keeps track of
calls of
> engineDoFinal(). if this varaible is set when
> entering either engineDoFinal () or engineUpdate(), engineInit () is
called
> again to reinitilize the cipher, resulting in some
> runtime overhead
>
> My question is: will this difference be fixed or will there be any
future method
> to reset only the IV
> without reinitilizing the whole cipher ?
>
>
> --
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>
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>
>


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*   From: "Andreas Sterbenz" <Andreas.Sterbenz@iaik.at>                   *
*   Date: Fri, 27 Oct 2000 09:49:50 +0200                                 *
*   Subject: Re: [iaik-jce] DES - Implementation of IAIK and IV           *
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