MDC & Symmetric

[David Shaw]

On Tue, May 21, 2002 at 08:45:54AM +0200, disastry@saiknes.lv wrote:

> David Shaw dshaw@jabberwocky.com wrote:
> > 
> > On Mon, May 20, 2002 at 11:30:58AM +0000, Aurelio Turco wrote:
> > > Does gpg's symmetric encryption also benefit from
> > > MDC (Modification Detection Code)?
> > 
> > Yes.  Since unlike PK encryption, there is no way to tell if the
> > recepient can handle it, it is off by default.  You usually need to
> > turn it on via --force-mdc.
> 
> >  It is on by default on all of the >128bit ciphers.
> > David
> 
> so this includes 3DES (it's 168 bit) and excludes AES128? ;->>
> no,
> this is default for all ciphers with blocksize >= 128bits:
> AES128/192/256 and Twofish.

Sorry - I did indeed mean block size, and not key size.  However, what
you say above is not correct: it's block size > 128.  AES128 is not
included here.

David

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   David Shaw  |  dshaw@jabberwocky.com  |  WWW http://www.jabberwocky.com/
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