Re: [Monotone-devel] WARNING: ~/.monotone/keys CONSIDERED HARMFUL

[Markus Wanner]

Hi,

Daniel Carrera wrote:
> My position is that what the PGP web of trust provides identification
> but not authorization and so it does not help Monotone.

According to your own definition below, PGP only provides
authentication, not identification.

I'm thinking of "identification" in broader terms than just assigning a
name and/or email address. For example, visual identification also
counts (but is obviously pretty useless for monotone).

To authorize someone to do something, you certainly need authentication.
Otherwise, how do you know who you authorize to do something?

> It isn't a web of trust. But as you imply, what we call it doesn't
> matter. Just call it policy or whatever.

If I'm publishing my server's policy and someone else adopts it, that
"someone else" trusts me enough to use the same ACL on his monotone
server. This doesn't need policy branches, but it's already possible
with today's monotone, and not even improbable.

I for example have granted write permissions on my server to somebody I
don't know in person. I only know others trust him enough to have commit
access on net.venge.monotone. Why should that not be a web of trust? A
pretty manual one (because we still need to exchange policies manually),
yes, but it certainly still is a web of trust, IMO. Policy branches are
(partly) about automating that aspect.

> The real issue is whether there
> is any benefit to using PGP from inside Monotone. I opine that there
> isn't. The things Monotone needs (authorization), PGP does not
> facilitate. The things that PGP provides that Monotone lacks (web of
> trust, identification), are not things Monotone needs. Just my opinion
> though.

As pointed out above, you certainly need authentication within monotone.
 Using GPG from monotone would allow to authenticate someone by his GPG
key instead of by his monotone key. And GPG keys are much more wide
spread than monotone keys, which might be a reason to at least support
GPG. Anyway, that's certainly not on top of my priority list for
monotone ;-)

> Trying to not start an argument about the definition of
> "identification", notice that what PGP provides which Monotone doesn't
> is assurance that the name and email actually match the key.

I'd state that PGP provides authentication - pretty independently of the
name and email. As an example, I've just recently changed my name due to
marriage, but the PGP key and my identity remained the same. I simply
added my new name, now having "Markus Schiltknecht" and "Markus Wanner"
as names for my identity.

> the guy who owns this key

.. that's exactly the "identity" part of the story. Just replace "this
key" with a GPG key and you could theoretically throw away monotone
keys. (Not that I'd want to do that)

> should be allowed into the server. For that purpose, PGP doesn't appear
> to provide anything that Monotone's light-weight alternative doesn't
> already provide.

I absolutely agree to that from a technical point of view. But it
requires people to create monotone keypairs, whereas by supporting GPG,
they could use their existing GPG keypairs.

> Now, on "identification": I think the following might be a relevant
> example: Imagine an ID card that has a picture of you but no name. You
> and I might disagree on whether we would call this identification.

I'd certainly call that (visual) identification, yes.

> But
> it might clear up confusion if I say that this is an example of what
> Schneier means by "no identification". In Schneier's lingo, this ID card
> may provide authentication but not identification. In my recent emails I
> have tried to follow Schneier's lingo.

Well, yeah, in that sense, both, the GPG key as well as the monotone key
only provide authentication but not identification, because it's always
possible that the key got stolen. But how's that point relevant between
GPG keys and monotone keys? It's not like monotone keys are any safer in
that regard than GPG keys.

Regards

Markus Wanner