Keys not trusted

Fri May 9 13:27:02 2003

Hash: SHA1

On Tuesday 06 May 2003 04:03 am, Wolfgang Bornath wrote:
> Being fairly new in this I joined this list and received some
> messages by people who signed their messages. I always imported the
> keys (using the gpg option --auto-key-retrieve) and kmail tells me
> "Message is signed by XY (blahblub) (Key-ID: 0x12345678).
> Signature is valid but the key is not trusted."
> When I want to send a private mail to somebody like that and I want
> to encrypt the text I see the list of my pubring but all imported
> keys are marked red and I cannot encrypt.

You're certainly not the only person with this problem. I know at
least some of the Kmail developers read this list, so may be it would
be useful to start a discussion on the matter. I think Kmail, and
mail agents in general, need some way of sending e-mail to unknown
parties.  Just because I don't know someone's real identity, doesn't
mean that I don't want to send them mail.  And it certainly doesn't 
mean that I want to add all these letters to a TIA (Total Information
Awareness) database, or in general share these letters with every
Eve, Carnivore, and archiving SMTP server between our two computers.

One way to pick the best key for such e-mail only acquaintances would
be for people within various communities to all use a single robot
authentication authority (for example:  Some members of this list, such as
GnuPG developer David Shaw, consider this to be a bad idea.  Shaw
proposes that when no trust path to an e-mail exists, the mail client
should encrypt to all available keys for the given e-mail address
(warning the user appropriately). Then when/if the party you sent to
replies, you can set the definitive key based on the key they use in
their reply.  (For this to be accessible to non-crypto zealots, the
mail agent would also need some way of locally signing a key based on
the signature of a received mail.)

I can think of a couple other ideas that would involve caching
previously seen address/fingerprint pairs.  Maybe with an SSH like
feature that warns when an address/fingerprint doesn't match the
address/fingerprint previously seen.  (All my ideas have minor
problems, so I'll wait and see what other people have to say first.)

Do the developers of Kmail, Sylpheed, and/or Enigmail have a vision of
how the mail agent of the future can increase the use of PGP for
casual Internet communications without making major compromises on
the security of more serious communications with known entities?

 - Yenot
Version: GnuPG v1.2.2 (GNU/Linux)