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

[Daniel Carrera]

Markus Wanner wrote:
> > The last point is interesting, and it seems sensible to me.
>
> Hm.. I don't see how running our own PKI should be different. Our
> web-of-trust is just very simple (and maybe doesn't deserve the term
> "web"): every server allows certain keys commit access to certain
> branches, only read access to other keys.

My position is that what the PGP web of trust provides identification 
but not authorization and so it does not help Monotone. If Brian and I 
have met in person and he signed my PGP key, and you trust Brian, you 
can be confident that that key really belongs to Daniel. But what does 
that buy you? It doesn't tell you whether Daniel should be allowed into 
the server. You still need to decide, independently, whether Daniel 
should be allowed in the server and if so, upload Daniel's key.

Notice the following:

1) PGP's web of trust did not reduce or alter the work needed to 
authorize Daniel.

2) PGP's web of trust provides identification, but what you are looking 
for is authorization. You don't really care if my name is Daniel or not. 
What you want to know is whether the guy who owns this key (the one who 
claims to be called Daniel) should be allowed into the server.



> Considering that we may be sharing these "policies" between servers
> manually, isn't that a sort of a web of trust? If you don't call it that
> now, you probably will with policy branches.

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

> Without knowing a name, yes. But is the name really the answer to the
> question "who are you"? (This is getting philosophical...)
>
> I'd argue that to authenticate *someone* to do something, you always
> need to identify the *someone* first. That doesn't necessarily mean
> getting his name. You can easily authenticate by confirming that it's
> the same person who has written revision 276264b0... for example.

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. This is the 
thing which (whatever we call it) we have agreed Monotone does not care 
about. Monotone only cares about whether the guy who owns this key 
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.


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. 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.


Daniel.