WebApp Sec mailing list archives

RE: Summary: Growing Bad Practice with Login Forms


From: "Mike Peppard" <mpeppard () impole com>
Date: Thu, 29 Jul 2004 09:30:56 -0400

Something like a database of unique graphics and you know you're 
secure if the site has hashed your password and chosen "your" graphic 
to put in the upper corner of every page?

This sort of solution only would help a people who are already
conscientious.  How many people would want to go to the extra trouble
of establishing such an image and then remembering the images.

You make them, just like you make them use a PIN. I'm also talking about
higher security sites. Banks and the like. For a shopping cart at "Joe's
Internet automart" this makes no sense, but problems would be covered
under creditcard insurance there.

I'm thinking about the procedure:
1) I go to your site and check ssl is on.
<Assumption is that "your site" is the site I really wanted to go to.>
2) I put in my private information.
3) You send me back a graphic.
<Assumtion is that we are the only ones who know the graphic.>
4) I have to send a reply back that the graphic I see is the
correct graphic. It may take a couple of trys.
5) The "good site" now knows I have the password and know the graphic.
<Assumtion is that having the graphic and password makes me the owner
of the graphic and password, not the phisher.>
6) I check each page for the graphic.
<Assumption is that I'm safe if I see the graphic.>
7) If the graphic is wrong or disapears, I call the bank right away.
<Assumption is that I care enough to do it.>

It's the assumptions that bother me and how to ensure minimal damage
can occur before dual verification happens. The graphic can be assigned
from a large database of graphics randomly and be effective. A person
confronted with a pic of children playing would be disconcerted when
the reply graphic had... say... black and white blocks on a table.


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