- From: Serge Egelman <egelman@cs.cmu.edu>
- Date: Sat, 21 Jul 2007 17:32:15 -0400
- To: Mary Ellen Zurko <Mary_Ellen_Zurko@notesdev.ibm.com>
- CC: "'W3C WSC Public'" <public-wsc-wg@w3.org>
Umm, yeah, that's the exact same paper that I sent out :) serge Mary Ellen Zurko wrote: > > I would also recommend: > > http://cups.cs.cmu.edu/soups/2005/2005proceedings/p13-garfinkel.pdf > > to see it's use in a context (email), and get a sense of its strengths > and weaknesses (not so hot for bootstrapping attacks, but great for the > continuity thing it's named after). > > Mez > > > > public-wsc-wg-request@w3.org wrote on 07/19/2007 11:39:00 AM: > >> [image removed] >> >> Re: ACTION-240 :TLS errors... >> >> Serge Egelman >> >> to: >> >> Dan Schutzer >> >> 07/19/2007 11:44 AM >> >> Sent by: >> >> public-wsc-wg-request@w3.org >> >> Cc: >> >> "'Johnathan Nightingale'", "'W3C WSC Public'" >> >> >> I haven't done any work on it. But this might help: >> >> http://portal.acm.org/citation.cfm?id=1073003 >> >> Read the references as well, if you're not familiar with them. I'm sure >> you can download the paper elsewhere if you google for it. >> >> serge >> >> >> Dan Schutzer wrote: >> > Can you send me some references to your work in Key continuity > management? >> > Thanks >> > >> > Dan >> > >> > -----Original Message----- >> > From: public-wsc-wg-request@w3.org > [mailto:public-wsc-wg-request@w3.org] On >> > Behalf Of Serge Egelman >> > Sent: Wednesday, July 18, 2007 10:11 AM >> > To: Johnathan Nightingale >> > Cc: W3C WSC Public >> > Subject: Re: ACTION-240 :TLS errors... >> > >> > >> > Righto, I now see what he meant and am in complete agreement. This is >> > delving into not just keeping track of root certificates (which I think >> > you all know my opinion on), to keeping track of every certificate. >> > Peter Gutmann and Simson Garfinkel have done some work on this-- "key >> > continuity management", and I think this would be a good recommendation >> > for us to make. It's trivial to keep track of every host/certificate >> > tuple, just as browsers already keep track of form information. >> > >> > serge >> > >> > Johnathan Nightingale wrote: >> >> On 18-Jul-07, at 9:48 AM, Serge Egelman wrote: >> >> >> >>> Well, you said that this "is the poster child for exploiting browser >> >>> state." For it to be a serious threat that warrants > consideration, you >> >>> must assume that most users read certificate data (regardless of > whether >> >>> the browser is actually throwing a warning). If we can assume > that most >> >>> users do *not* read this information, then there's a plethora of much >> >>> easier/likelier attacks. >> >>> >> >>> That is, it's a waste of time worrying about how a burglar might pick >> >>> your fancy new lock when you regularly leave all the windows open. >> >> Serge, >> >> >> >> I might be wrong here, but I think you are talking past each other >> >> because I think you are misunderstanding Thomas' use of the word >> >> "exploiting". His original quote, in response to the discussion about >> >> using a self-signed cert to facilitate a man in the middle attack, was: >> >> >> >>> Isn't this a poster child use case for exploiting browser state? >> >>> E.g., exploiting the knowledge that a certain domain in connection >> >>> with HTTPS used to have a CA-based cert, and warning when that >> >>> changes? >> >> By which I believe he meant: "This nicely illustrates why it would be >> >> useful for browsers to maintain state about prior SSL connections so >> >> that, in the event - however unlikely - that you visit a site which > used >> >> to have a CA-signed cert, but which now instead presents a self-signed >> >> one, the browser can make all manner of noise/aggressive blockage, > since >> >> that scenario is magnificently unlikely for any legitimate bank, >> >> webstore, etc." >> >> >> >> I think he meant "exploiting browser state" as "leveraging browser > state >> >> to do good things for users" not "attacking browser state, here's a new >> >> threat for us to consider." >> >> >> >> As I say, maybe I'm wrong, and you're reacting to the idea as I >> >> (re-)expressed it, but one of us is being tripped up by email-fail, >> >> because I'm having trouble following your arguments against (what I >> >> understand to be) his point. >> >> >> >> Cheers, >> >> >> >> Johnathan >> >> >> >> --- >> >> Johnathan Nightingale >> >> Human Shield >> >> johnath@mozilla.com >> >> >> >> >> >> >> > >> >> -- >> /* >> Serge Egelman >> >> PhD Candidate >> Vice President for External Affairs, Graduate Student Assembly >> Carnegie Mellon University >> >> Legislative Concerns Chair >> National Association of Graduate-Professional Students >> */ >> > -- /* Serge Egelman PhD Candidate Vice President for External Affairs, Graduate Student Assembly Carnegie Mellon University Legislative Concerns Chair National Association of Graduate-Professional Students */
Received on Saturday, 21 July 2007 21:32:47 UTC