It's my understanding that Captchas are to prevent hackers from
hacking into specific sites and/or e-mail. They usually have pictures
to glong with he scrambled voices. Richie Gardenhire, Anchorage,
Alaska.
On Sep 24, 2008, at 10:16 PM, Jane Lee wrote:
Actually, the biggest problem with captchas is that employing a
human to
read them is cheap enough in many cases with a higher hit rate than
OCR.
While google and the like will have an increasingly hard time
figuring out
the legitimate users from the spammers, most small sites can get
away with a
different type of captcha, I've mentioned this on twitter before,
but one
such implementation is at lemurcatta.org. Works fantastic for blogs -
basically get the user to select what was mentioned in the blog post
they're
attempting to comment on, and possibly ask some additional questions
only
readers of the blog would know how to answer. Very trivial if you're a
legitimate person wanting to comment, a bit harder and possibly not
worth
the effort if you're a random troll or spammer.
cheers,
jane
On Wed, Sep 24, 2008 at 1:41 PM, Chris Blouch <[EMAIL PROTECTED]> wrote:
This was discussed at length on the list previously so you might
want to
check the archives. That said, it's mainly a cognitive puzzle that
tries to
validate that you are a person and not some script trying to gain
access.
Visual captchas are usually letter which have been swirled around
with noise
to be hard for an OCR program to read and hard for a real person as
well.
Audio captchas do similar things to spoken letters. I suggested
before that
this is an arms race which will end badly. Either the captchas will
get so
hard to discern that people can't get in or the scammer's
algorithms will
improve to the point where captchas add no security. Either way
captchas
will become useless.
CB
Jude DaShiell wrote:
The purpose of captcha is to make it nearly impossible for sighted
people
to log in and impossible for the rest of us.
On Wed, 26 Mar 2008, UCLA Bruins Fan wrote:
Can anyone tell me what the function of CAPTCHAS is supposed to
be? Why
are they needed on so many sites? Do they really perform any
function other
than making it difficult for blind users to access sites?
Olivia
