Encrypting to different UIDs ? Use of subkeys ?

[David Shaw]

On Wed, Apr 24, 2002 at 08:39:43AM -0400, Toxik - Fabian Rodriguez wrote:
> Hello,
> 
> I'd like to know if it makes any difference to encrypt data to different
> UIDs of the same key. This may not make sense, but I am using WinPT and all
> UIDs of a key are presented when choosing a key to encrypt to. I think it's
> rather confusing, but wanted to make sure.

Believe it or not, it can make a difference although it usually does
not.  Each different UID can have a different set of preferences
attached, which influence how the data is encrypted to you.

For example, say you use the same key for home and work.  At home you
like AES, BLOWFISH, and 3DES.  Your work requires TWOFISH, CAST5, and
3DES.  If you set the preferences properly, someone encrypting to your
home address would then use a different cipher than someone encrypting
to your work address.

All that said, people usually have the same preferences for all user
IDs and so in that case it does not matter.

> And another more general question, does this apply to subkeys ? What would
> be the use of creating/having subkeys ? The FAQ only mentions "use in an
> automated environment" (4.14).

Preferences do not attach to subkeys, but multiple subkeys in general
would of course mean a different key to encrypt to.

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