Re: Different protections for different kinds of spoofing (Was: PII Editor Bar & Trusted Browser Component)

I saw your responses to a and b, and just replied to one of them (the one on
burden). I'm going out of order here, but oh well. Anyhow, with spoofing, I
guess I am really skeptical. Even when the user chooses a picture (i.e.
Passmark SiteSecure), they can be easily phished. (I seem to recall a study
where the SiteSecure picture was replaced with "Not Available, server
maintenance" or something like that, and users went right on by). I'm really
worried that similar attacks are likely to work against PII-bar. And
frankly, if you can get users to only use a trusted interface to input login
credentials, there's much more exciting things (and much stronger protection
too) that you can do than just expecting users to notice some text they
entered. The problem is that I really believe getting users to only input
data into a trusted interface is the much harder part of the issue, and I
don't think we've addressed that sufficiently.

On 8/29/07, Close, Tyler J. <tyler.close@hp.com> wrote:
>
>  Hi Ian,
>
> I've responded to your points a) and b) respectively in:
> http://lists.w3.org/Archives/Public/public-wsc-wg/2007Aug/0199.html
>  http://lists.w3.org/Archives/Public/public-wsc-wg/2007Aug/0200.html
>
> In this email, I'm responding to your point c).
>
> There are many different kinds of spoofing attacks. The PII bar proposal
> text currently explains defenses against at least 4 different kinds. See:
> http://www.w3.org/2006/WSC/drafts/rec/Overview.html#piieditor-usecases-imposter
>
> http://www.w3.org/2006/WSC/drafts/rec/Overview.html#piieditor-usecases-spoofing
>
>
> Different elements of the PII bar proposal compose to defend against
> different attacks. In your email quoted below, you seem to be concerned with
> a Picture-In-Picture (PIP) spoofing attack, where the PII bar user interface
> itself is impersonated by the attack page. The petname display is not part
> of the defense against this attack. The petname helps in the defense mounted
> against other kinds of spoofing attacks, as documented in the first URL
> given above.
>
> The PIP defense offered by the PII bar proposal is documented by the
> second URL given above. This text currently says:
>
> """
>  Spoofing the PII Bar
>
> Spoofing of the PII bar itself is less of an issue than spoofing of the
> URL bar, since a spoofed PII bar does not contain the user's PII text
> strings and so may be recognized as a spoof. Alice's attempt to login using
> a spoofed PII bar is interrupted in step 6 when she is unable to select her
> password from the list of previously submitted text strings.
>
> For robustness against spoofing, the PII bar MUST be displayed using a
> theme customized to the user. The user selects this theme at browser
> installation time and it remains forever the same. The icon for the Contacts
> button MUST also be selected by the user at installation time.
> """
>
> I think there has been some study of customized chrome in the past and the
> results were not promising; however, I suspect we can do better. The Jackson
> study found that users attached no significance to the new style chrome in
> IE7. I hope the PII bar customization will fare better because it will be
> chosen by the user. I also think some habituation time will reinforce the
> user's expectation that the PII bar should be displayed in their chosen
> theme and that something is broken if not. Obviously, we need to test this
> though.
>
> --Tyler
>
>  ------------------------------
> *From:* Ian Fette [mailto:ifette@google.com]
> *Sent:* Tuesday, August 28, 2007 5:09 PM
> *To:* Close, Tyler J.
> *Cc:* public-wsc-wg@w3.org
> *Subject:* Re: PII Editor Bar & Trusted Browser Component
>
> I know we're planning to do usability studies on all sorts of things, but
> I am going to bring this up at tomorrow's meeting and ideally I'd like to
> get over the "But studies show X" responses that I feel are inevitable
> around these topics.
>
> So, with that said:
>
> Can anyone point me to the relevant papers that show
> a) Just how much of a burden this is
> b) That users will actually figure out that there is a problem when
> they're being told to enter their username/password into some Flash movie (
> i.e. the formfiller is never triggered so PIIbar doesn't get to show any
> warnings)
> c) Resiliency against spoofing (i.e. if I just guess that "paypal" is
> probably reasonable pii text for paypal.com and show that in a spoofed
> display to the user, is the user actually going to notice that this is not
> their pii text (assuming that they chose something different)
>
> My biggest concern is that we seem to be on a warpath to say "X provides
> protection because study Y shows a statistically significant difference
> under some set of controls for some task", while not really trying to
> quantify the burden on users and figuring out whether a) this is acceptable
> under real usage b) How much dollars lost this burden translates into and c)
> whether these dollars lost from b are actually worth it. I.e. just because
> some users perform better in a lab study on some task doesn't necessarily
> translate (for me) to "We should impose this burden on people, which will
> probably result in a non-negligible number of transactions being aborted due
> to user frustration, all in the name of some marginal improvement that can
> still be spoofed and really hasn't been tested to scale yet."
>
> That's my fear, I will q+ already for tomorrow's meeting, but ideally I
> wanted to get some of it out of the way ahead of time.
>
> -Ian
>
> On 8/28/07, Close, Tyler J. <tyler.close@hp.com> wrote:
> >
> >
> > I've collected together some links and more comments to help out with
> > tomorrow's Agenda item: "8. PII Editor Bar" [1].
> >
> > Many of the questions in TLR's first pass [2] over the PII bar were
> > covered in last week's telecon, as well as in my response to Rachna's
> > first pass [3]. I suggest looking over this response, in addition to
> > reading the proposal itself again [5]. In particular, there's been some
> > confusion over secure attention keys, like the Windows CTRL-ALT-DEL
> > sequence. The PII bar *does not* require a secure attention key. If
> > someone could point to the text that is causing this confusion, that
> > would help.
> >
> > In TLR's email [2], he wondered about providing a secure data entry
> > interaction for all sensitive data, as opposed to just special casing
> > username/password data. I think our charter and our use-cases require
> > providing protection for a broad range of PII data, such as credit card
> > numbers, social security numbers, phone numbers, etc. Moreover, I don't
> > seen anything to be gained at this stage from focusing only on login
> > forms. I believe the proposed form filler changes can be made just as
> > usable as any password-only manager that can be deployed on today's Web.
> >
> > TLR's email also supposed that both proposals "get most of their
> > protection out of the
> > user's lossy memory". I think both proposals actually get most of their
> > protection from the data entry interaction, not on any reliance on the
> > user's not remembering sensitive data. I agree there is useful
> > protection to be had from freeing the user from the task of remembering
> > passwords, and that both proposals enable this.
> >
> > I think the remaining parts of TLR's email need to be presented in more
> > detail to be effectively examined. Thomas, what do you think about
> > phrasing some of your questions in terms of our use-cases [6]? For
> > example, picking one that you think reveals a shortcoming and
> > pinpointing the exact moment where the user may be tempted to follow a
> > detrimental course.
> >
> > --Tyler
> >
> > --
> > [1] "Agenda: WSC WG weekly 2007-08-29"
> >
> > <http://lists.w3.org/Archives/Public/public-wsc-wg/2007Aug/0157.html >
> >
> > [2] "PII Editor Bar & Trusted Browser Component from Thomas Roessler on
> > 2007-08-16 (public-wsc-wg@w3.org from August 2007)"
> >
> > < http://lists.w3.org/Archives/Public/public-wsc-wg/2007Aug/0127.html>
> >
> > [3] "Rachna's first cut at a usability analysis of PII bar"
> >
> > <http://www.w3.org/2006/WSC/wiki/RecommendationUsabilityEvaluationFirstC
> > ut#head-19caf4993d486f3f77f40171acc200d22fbf016e>
> >
> > [4] "RE: first cut usability walk through from Close, Tyler J. on
> > 2007-08-06 ( public-wsc-wg@w3.org from August 2007)"
> >
> > <http://lists.w3.org/Archives/Public/public-wsc-wg/2007Aug/0029.html >
> >
> > [5] "Personally Identifiable Information (PII) Bar"
> >     <http://www.w3.org/2006/WSC/drafts/rec/Overview.html#piieditor >
> >
> > [6] "Note - use cases"
> >     <http://www.w3.org/2006/WSC/drafts/note/#scenarios >
> >
> > -----Original Message-----
> > From: public-wsc-wg-request@w3.org [mailto:public-wsc-wg-request@w3.org]
> > On Behalf Of Thomas Roessler
> > Sent: Thursday, August 16, 2007 10:19 AM
> > To: public-wsc-wg@w3.org
> > Subject: PII Editor Bar & Trusted Browser Component
> >
> >
> > I'm reading through the latest state of the PII Editor Bar proposal,
> > and also the Trusted Browser Component proposal again.
> >
> >   http://www.w3.org/2006/WSC/drafts/rec/Overview.html#piieditor
> >   http://www.w3.org/2006/WSC/wiki/TrustedBrowserComponent
> >
> > There are a number of differences on a detailed level -- e.g.,
> > petnames vs generic shared secrets, and some stuff like that.
> >
> > I *think* the one significant difference between the two is that PII
> > Editor Bar proposes a different interaction ritual for generic
> > forms, and requires significant customization (i.e., the "data
> > entry" task is redesigned), while the Trusted Browser Component
> > seems to focus on a single high-level task ("login to XXX") and
> > introduces a new (possibly simpler?) user interaction for that more
> > narrow task.
> >
> > Both proposals seem to get most of their protection out of the
> > user's lossy memory (if people don't remember passwords, they won't
> > easily hand them over), and the broken interaction flow when people
> > log in to an unkown site that they think is the one they were at
> > before.
> >
> > Both proposals include some social engineering to steer users toward
> > a site they've dealt with before in certain failure cases, by making
> > it easy for them to find out about "existing relations" during the
> > interaction that would lead to data entry with the site they
> > currently deal with (and caching of that data / passwod).  I like
> > that part, and would love to see some empirics on the effect.
> >
> > PII Editor Bar gets a second level of protection out of a
> > petname-like UI paradigm; the Trusted Browser Component assumes that
> > some kind of shared secret has been established to create a trusted
> > path to the user.  Mentally going through possible scenarios, I'm
> > suspecting that this particular element of the respective proposals
> > is the weakest one.
> >
> > As we move forward, I would like to see both concepts -- the generic
> > form filler, and the task-specific approach -- tried out and
> > analyzed.  I have a gut feeling that the task-specific approach that
> > the Trusted Browser Component suggests might have larger chances for
> > deployment and user acceptance, based on ease of use when people log
> > in to sites.
> >
> > It might in this context be worth looking at the difference between
> > approaches that (a) require a secure attention key, (b) require a
> > secure attention key and tell the user about it ("to login to XXX,
> > please push blah", maybe in one of the nice yellow
> > chrome-overlapping bars), and (c) don't require a secure attention
> > key, but simply replace the login interaction.
> >
> > (Example: PII bar seems to require that a secure attention key be
> > pressed for every single form field.  TBC seems to only require some
> > specific interaction to either put a session into a specific mode,
> > or maybe to effect a login transaction.)
> >
> > Additionally, it might be an interesting exercise to abstract one
> > step further, and beyond documenting the specific approach that
> > comes out useful as a secure data entry ceremony, also write up some
> > general requirements for secure, interactive credential selection
> > and/or login processes.
> >
> > Thoughts?
> > --
> > Thomas Roessler, W3C  <tlr@w3.org>
> >
> >
> >
>