Symmetric cipher selection order, RSA keys

David Shaw dshaw@jabberwocky.com
Wed May 22 22:34:02 2002


> On Fri, May 17, 2002 at 01:54:57PM -0400, David Shaw wrote:
> > On Fri, May 17, 2002 at 04:30:51PM +0000, Brian M. Carlson wrote:
> > > On Mon, May 13, 2002 at 07:29:08AM -0700, David Hollenberg wrote:
> > > > 
> > > > 1. Suppose I encrypt a message to two public keys, whose symmetric
> cipher
> > > >    preferences are:
> > > > 
> > > > 	Key 1:  AES, CAST5, 3DES
> > > > 	Key 2:  CAST5, AES, 3DES
> > > > 
> > > >    Which cipher will GNUPG pick?  Can I influence GNUPG's choice
> > 
> > Anyway, GnuPG will pick either AES or CAST5 in this case, depending on
> > the order in which the keys are given during encryption.  You can
> 
> After thinking about this some more, I think that a list of algorithms
> that the user favors is a good idea.  I've added
> "--personal-preference-list" to the CVS.  GnuPG will take this list
> into account when picking algorithms.

On Wed, May 22, 2002 at 01:29:43PM -0700, Steve Butler wrote:

> Would it be an ordered list so that the left most item left in the
> intersection would take precedence?  That way if my personal list was:
> CAST5, AES256, AES, 3DES  then CAST5 would be picked (based on the two below
> keys).  However, if I listed AES256, AES, CAST5, 3DES then AES would be
> picked.

Exactly correct.  It is an ordered list.

David

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