Re: [ietf-smtp] Public Key Look Up

[John C Klensin <[e-mail]>]

--On Wednesday, May 12, 2021 19:04 +0200 Alessandro Vesely
<[e-mail]> wrote:

>... 
>> Indeed.  But if the keys include signatures, it doesn't
>> matter where they come  from, so we're back to asking why
>> nobody seems to use the key servers that  already exist.
> 
> Some people has been using those key servers.  However,
> they're vulnerable to pgp-poisoning attacks[*].
>...
> [*] https://github.com/skeeto/pgp-poisoner

We are getting fairly far off-topic, but ...

There is an extremely straightforward way to resist such
attacks, which is to accept key updates only from the
authenticated key owner or, _maybe_ from one of the existing
signatories whose key is already in the repository.  There are
issues there too, but most of them come down to something John
Levine pointed out earlier in the thread (and that has been
known since the 1990s), which is that PGP's web of trust concept
does not scale very well.  I can think of another defense too,
but, again, we are getting fairly far off-topic.

But, Ale, it seems to me that almost everyone but you is saying
things that ultimately lead to the same place: either that it
would not be a good idea to try to build this into SMTP or that,
we we did, it either wouldn't work or there would not be enough
uptake and deployment to make it useful.  That does not
necessarily mean that we are right and you are wrong, but it
does suggest that this thread is nearing the end of its useful
life.

best,
    john