Re: [PLUG] confirming my identity

[Jeff Abrahamson <jeff@PURPLE.COM>]

On Wed, Jul 11, 2001 at 05:15:08PM -0400, Dave Turner wrote:
> Jeff Abrahamson wrote:
> > 
> > On Wed, Jul 11, 2001 at 02:38:05PM -0400, Darxus@chaosreigns.com wrote:
> > > My public key, as you may have noticed, does not have any information on it
> > > that can be confirmed by photo ID:
> > >
> > > pub  1024D/0E9FF879 2000-09-05 Darxus <Darxus@ChaosReigns.com>
> > >      Key fingerprint = DE37 8846 3B06 B97C F661  D68F 7FB5 B0BE 0E9F F879
> > > sub  1024g/2EEAB976 2000-09-05
> > >
> > >
> > > It's been signed by a number of plug regulars who know, personally,
> > > who I am.  If you don't, you may want to consider alternate methods of
> > > verifying my identity, so you can sign my key.
> > >
> > > Like emailing me a password/phrase, so that only I (the person with the
> > > email address darxus@chaosreigns.com) would know it, and so you could
> > > know who me is.
> > 
> > But then how do I know that you didn't cleverly intercept the mail
> > from the real darxus?
> > 
> > ;-)
> > 
> > --
> >  Jeff
> > 
> >  Jeff Abrahamson  <http://www.purple.com/jeff/>
> 
> Because you encrypted the message using his public key, and you brought
> with you the fingerprint of the key you encrypted with.  So, the person
> you meet at the meeting has the same keys as the person who has the
> e-mail address.

True, but the extremely paranoid point is that all I know is that the
key belongs to a human being (presumably ;-), an entity capable of
attending a meeting and reading mail. I don't know *who* it is. And
that's part of the point of the signing.

In other words, he can't provide further proof of who he is except
that he's darxus@chaosreigns.

If his key said "Jon Johanssen" and he shows up at the meeting with
his Finnish passport saying that he's Jon J himself, then I know
something more about what I'm signing. It's still possible to fake,
but it's just harder.

Consider the following: I kidnap the real Darxus, then I adopt his
email persona. I'm a programmer, so I even write some cool free
stuff. Now I issue a key signed darxus, then come to the
meeting. People sign my key, because they did what you propose above.

Now, I release Darxus (maybe ;-). He can't very well revoke the signed
key. It's thorny. (He would get other people to sign a new key, of
course, and to revoke their signatures of his key. But it's much
harder.

This is all very paranoid, but that's what the web of trust is about.

-- 
 Jeff

 Jeff Abrahamson  <http://www.purple.com/jeff/>



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