Re: [tcpinc] Eric Rescorla's Discuss on draft-ietf-tcpinc-tcpcrypt-09: (with DISCUSS and COMMENT)

["Black, David" <[e-mail]>]

Posting mostly to merge email threads back into one thread - IMHO, the following exchange seems to capture the state of things and subsumes the details that the other (my) thread with Ekr had gotten into:

> > With that said, it's not clear to me that the WG actually did have consensus
> > that this brittleness was a good tradeoff. Was this property in fact widely
> > understood? Speaking only for myself, it really only came into focus for me
> > when I did my review.
> 
> No, I think you're right that this wasn't widely understood, or at
> least not discussed. That wasn't what I was referring to, however: I
> do think the brittleness is worth at least discussing on the list
> (check) and seeing if there's consensus to make a change to the
> protocol or to add a crystal clear warning to the draft explaining the
> critical importance of not reusing SIDs.

Thanks, --David

> -----Original Message-----
> From: Kyle Rose [mailto:[e-mail]]
> Sent: Monday, November 27, 2017 12:58 PM
> To: Eric Rescorla <[e-mail]>
> Cc: Daniel B Giffin <[e-mail]>; Black, David
> <[e-mail]>; tcpinc <[e-mail]>; [e-mail];
> The IESG <[e-mail]>; [e-mail]
> Subject: Re: [tcpinc] Eric Rescorla's Discuss on draft-ietf-tcpinc-tcpcrypt-09:
> (with DISCUSS and COMMENT)
> 
> On Mon, Nov 27, 2017 at 12:36 PM, Eric Rescorla <[e-mail]> wrote:
> > On Mon, Nov 27, 2017 at 9:24 AM, Kyle Rose <[e-mail]> wrote:
> > I don't really think it's really worth relitigating this; I'm merely
> > observing
> > that if you want high resumption rates then you want stateless
> resumption.
> 
> For a server pool, I completely agree.
> 
> > As for the question of option space, I'm not persuaded it wouldn't
> > be possible to have stateless resumption with the same number of
> > round trip times if you were willing to be a bit more careful about
> > how you handled failure.
> 
> I would be interested in an (OOB) conversation on your thoughts here.
> 
> >> Agreed (though I am not sure Mirja will be happy to hear that). My
> >> comment about scope creep is simply that the WG came to a consensus
> on
> >> this topic (resumption tradeoffs) long ago, so I'm not sure we should
> >> be second guessing that judgment at IETF LC.
> >
> > I'm not sure what you think is being second guessed.
> 
> I was referring specifically to the resumption tradeoffs (rate vs.
> performance). That said, all I can find is this:
> 
> https://www.ietf.org/mail-archive/web/tcpinc/current/msg00919.html
> 
> which doesn't actually talk about that tradeoff, but rather about the
> charter's requirement for forward secrecy.
> 
> > With that said, it's not clear to me that the WG actually did have consensus
> > that this brittleness was a good tradeoff. Was this property in fact widely
> > understood? Speaking only for myself, it really only came into focus for me
> > when I did my review.
> 
> No, I think you're right that this wasn't widely understood, or at
> least not discussed. That wasn't what I was referring to, however: I
> do think the brittleness is worth at least discussing on the list
> (check) and seeing if there's consensus to make a change to the
> protocol or to add a crystal clear warning to the draft explaining the
> critical importance of not reusing SIDs.
> 
> Kyle