Subject: Re: Revocation key difficulty

From: "Michael Young" <[email-masked]>
Date: Tue, 5 Mar 2002 15:43:54 -0500

David Shaw noted this PGP (and now GnuPG) behavior:
> If the designated revoker's key is not present, then a key "revoked"
> by the designated revoker key is not treated as revoked.  GnuPG - as
> of this morning - does it the same way.

I would argue that silently ignoring a missing revoker is a bad default.
GnuPG is generally very good about issuing warnings (and offering
options :-).  Would you be willing to do so here (at least when
a potential revocation is present)?

I know this doesn't thwart would-be attackers.  They can always
remove the revocation itself.  A warning would simply help
recognize that the key is effectively incomplete, and that the
revoker should be retrieved.  (Or, have you adjusted GnuPG to
automatically retrieve revokers after retrieving a key from a server?)

A signed CRL could provide the means to defeat removal attacks.  I
thought that I'd seen a draft that had considered some form of CRL,
but I can't find it now.  Did that ever come up?  I understand that
this requires a bunch of specification, so I can see why it might have
been rejected.

---

From: David Shaw <[email-masked]>
Date: Wed, 6 Mar 2002 13:45:27 -0500

> a potential revocation is present)?

Good idea.  I think a warning during key import if a key has a
potential revocation on it is appropriate.

> automatically retrieve revokers after retrieving a key from a server?)

It doesn't, but that's a good idea as well (to be optional, of
course).

David

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David Shaw          |  Technical Lead
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