cipher prefs and cipher-algo settings

[David Shaw]

On Wed, Jun 19, 2002 at 12:47:20PM +0100, john clark wrote:
> 
> hi,
> 
> sorry for being naive but i would just like to clear
> some things regarding preferences and cipher-algo
> settings in the options file.
> 
> setpref would set your preferred cipher algorithms for
> you public key, right? so others who would send you a
> message would encrypt messages for you using the
> preferred algorithms.

Yes.

> will putting "cipher-algo newcipher" on your
> .gnupg/options file encrypt ALL messages using that
> algorithm, regardless of what the public key prefers
> you to use?

Yes.  This is a very bad way to do things as it overrides what the
public key owner asked you to use.  He may not even HAVE that
algorithm, and will not be able to decrypt the message at all.

"cipher-algo" (as well as "digest-algo" and "compress-algo") should
almost never be needed in regular usage.  Let the GnuPG program figure
out which algorithms to use - if you are using OpenPGP keys (GnuPG,
any PGP after v5) it will always pick algorithms that the public key
owner can handle.

David

-- 
   David Shaw  |  dshaw@jabberwocky.com  |  WWW http://www.jabberwocky.com/
+---------------------------------------------------------------------------+
   "There are two major products that come out of Berkeley: LSD and UNIX.
      We don't believe this to be a coincidence." - Jeremy S. Anderson