browser vendors and CAs agreeing on high-assurance certificates

[James A. Donald]

    --
Peter Gutmann
>   In fact the real situation is even worse than this. 
>   Although there has been plenty of anecdotal evidence 
>   of the ineffectiveness of SSL certificates over the 
>   years, it wasn.t until mid-2005 (ten years after 
>   their introduction) that a rigorous study of their 
>   actual effectiveness was performed. This study, 
>   carried out with computer-literate senioryear 
>   computer science students (who  one would expect 
>   would be more aware of the issues than the typical  
>   user) confirmed the anecdotal evidence that invalid 
>   SSL certificates had no effect whatsoever on users 
>   visiting a site.
>
>   [...]
>
>   A contributing factor in the SSL certificate problem 
>   is the fact that security warnings presented to the 
>   user often come with no supporting context. Since 
>   web browsers implicitly and invisibly trust a large 
>   number of CAs, and by extension a vast number of  
>   certificates, users have no idea what a certificate 
>   is when an error message mentioning one appears. One 
>   user survey found that many users assumed that it 
>   represented some form of notice on the wall of the 
>   establishment, like a health inspection notice in a 
>   restaurant or a Better Business Bureau certificate, 
>   a piece of paper that indicates nothing more than 
>   that the owner has paid for it (which is indeed the 
>   case for most SSL certificates). Users were 
>   therefore dismissive of .trusted. certificates, and 
>   as an extension cared equally little about 
>   .untrusted. ones.
>
>   This user conditioning presents a somewhat difficult 
>   problem. Psychologists have performed numerous 
>   studies over the years that examine people.s 
>   behaviour once they.ve become habituated into a  
>   particular type of behaviour and found that, once 
>   acquired, an (incorrect) whirr, click response is 
>   extremely difficult to change, with users resisting 
>   attempts to change their behaviour even in the face 
>   of overwhelming evidence that what they.re doing is 
>   wrong.

But is what they are doing wrong?

To solve the phishing problem (man in the middle attack) 
using certificates, not only must users become alarmed 
on encountering no certificate or a defective 
certificate, but businesses that may be potentially 
phished must faithfully and regularly employ 
certificates, which they do not consistently do, and 
faithfully and regularly sign their mail, which they 
almost never do, and must, like google or paypal, use a 
single user memorable brandnamed root to their domain 
names, which the new internet businessess generally do, 
for example "skype.com", but pre internet businesses 
generally do not do.  Further, businesses must fix all 
their servers so that redirects and the like are immune 
to cross scripting attacks and do full server side 
checking of all user input data, and must never solicit 
users to click on links that are full of large amounts 
of hidden gibberish.  Further email clients should never
allow a clickable post link within email, though at
present all of them do.

Since most businesses are not doing any of that, there 
is little incentive for even the most sophisticated user 
to worry too much about certificates.

Further, even if all the businesses start doing the 
right thing, we will never succeed in explaining to 
users that https://atbbr.bankofadelaide.com is safe 
while https://bankofadelaide.atbbr.com is unsafe.  

    --digsig
         James A. Donald
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     7lvFKmh9CI9ZQfYIy78zI4N2dRYic3ejlTGQRoao
     4R5oEEaOy/wO1wELCYESt8HByRqNhqN5UjF6Br4c3



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