Subject: [p2p-sip] Review of draft-bryan-sipping-p2p-02

From: ekr at networkresonance.com (Eric Rescorla)
Date: Mon, 13 Mar 2006 06:15:39 -0800

"David Barrett" <dbarrett at quinthar.com> writes:

>> -----Original Message-----
>> From: Eric Rescorla [mailto:ekr at networkresonance.com]
>> 
>> "David Barrett" <dbarrett at quinthar.com> writes:
>> >
>> > Given that a secure DHT is an unsolved problem, and given the IETF only
>> > deals with solved problems, should we:
>> >
>> > 1) Standardize the best practices today, despite their insecurity.
>> >
>> > 	-- OR --
>> >
>> > 2) Wait until a secure DHT has been invented and reconvene.
>> >
>> > I vote for #1.  I certainly don't vote for the unstated #3:
>> "Simultaneously
>> > invent and standardize a new variant of DHT that is secure (for some
>> > definition of 'secure')."
>> 
>> There's a point below which the security of the system is so bad
>> that it shouldn't be standardized. The question is whether
>> that's the case here.
>
> That's a fair question, how would you answer it?
>
> If your answer is "yes, DHTs are so insecure that standardization is
> pointless" then would you advise that we dissolve and reconvene later?
>
> If your answer is "no, DHTs aren't so insecure so as to make standardization
> pointless" then would you advise that we continue on our current path?
>
> Or do you have another answer such as "yes, the DHT we're currently
> discussing is so insecure that standardization is pointless, and therefore
> we should <insert alternate plan>."

As far as I can tell, the combined system described in this document
is so insecure that it should not be standardized. There may be some
hybrid system (e.g., along the lines of that described by Cox et al
<http://www.pdos.lcs.mit.edu/chord/papers/ddns.pdf>), most likely with
externally verified authentication that would be worth standardizing.

-Ekr

---

From: bryan at ethernot.org (David A. Bryan)
Date: Mon, 13 Mar 2006 09:51:27 -0500

Just to make sure everyone remembers, this draft isn't really intended
to be standardized in any way as it stands anyway (we say that in the
intro, and I've mentioned that in all my talks), instead it was
proposed as a "hey, here is how we might make this work, this is what
we are experimenting with" strawman, and the current iteration is
changes as a result of lessons learned in implementation, so I will be
the first to agree with Eric that as it stands this ain't even
remotely close to something to consider for standardization. It was
put out as a strawman to shoot at to come up with something useful, so
looks like it is working!

The security section in particular is really old (most of it from the
-00 draft that Cullen and I wrote over a year ago), and hasn't been
updated much since we largely have been working with the message
passing in our coding and wanted to share some things we thought
improved that work. I've actually had some conversations (several with
Eric, actually) where using centrally issued certificates (possibly
rate limited somehow), and storing fully verifiable certificate chains
in the overlay was suggested, and in fact seem the only way to truly
secure something like this. We are likely to look toward something
like that for the next iteration. I realize only addresses *part* of
Eric's concerns anyway, but I just want everyone to be clear about
what this draft is (strawman) and what it isn't (something that in
anything resembling its current form is being suggested as a
standard).

Heck, I'm hoping we get a new WG which can define better requirements
and architecture from many more sources and then we can get some folks
working on a better (and far more secure) idea for how to get this
done.

--David

On 3/13/06, Eric Rescorla <ekr at networkresonance.com> wrote:
> _______________________________________________
> p2p-sip mailing list
> p2p-sip at cs.columbia.edu
> https://lists.cs.columbia.edu/cucslists/listinfo/p2p-sip
>

---

From: dbarrett at quinthar.com (David Barrett)
Date: Mon, 13 Mar 2006 10:06:26 -0800

> Subject: Re: [p2p-sip] Review of draft-bryan-sipping-p2p-02
> 

Ahh, I understand.  Thanks.

-david