[SATLUG] Seeking robot immunity in my feedback form

[Sexton, Art, ISD]

 Wow...Digg is right on this topic today.  Here is an interesting
approach:

Here's an interesting thought. The flip side of "prove you aren't a
robot," is "prove you are human." 

Though it's no easier to prove, at least it places the onus of proof on
the spam bot and not your human guests. It's subtle, but there's a
philisophical difference between requiring people to do something that
is difficult for a machine, versus asking the machine to do what a real
human will do naturally.

Damien Katz writes about one way to approach this problem with the use
of CSS.


It's a neat idea, instead of asking the user to prove he's human, it
instead tricks the spam bot into revealing it's a bot. It does this with
a email field that is hidden from the user by CSS.

When a human user fills out the form, the hidden field will always be
blank. But when filled out by a spam bot, it doesn't know the field is
supposed to be hidden, so it adds a bogus email address and submits the
form. When the back-end code sees the email in the posting, it knows the
email was filled in by a bot and ignores the whole submission.


It's not perfect-this won't stop custom-coded spam attacks-but it does
kill some of the automated, roving, spider-based comment spam. Working
negative captcha methods into a dynamic changing-key system (much like
current captcha but transparent to your human users) is the obvious next
step, and I bet we'll be seeing (or should I say "not seeing") stuff
like this very soon. - Link.



The original site at
http://www.hackszine.com/blog/archive/2007/02/negative_captcha.html?CMP=
OTC-7G2N43923558 is probably down from the digg effect, but you can read
this as well on the mirror at
http://duggmirror.com/programming/Negative_Captcha


Interesting...

Art Sexton


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