Re: Google and Spam and Captcha.

Rich Grise wrote:
On Wed, 21 May 2008 16:38:57 +1000, Don McKenzie wrote:

JeffM wrote:
mpm wrote:
[...]Google Groups now has a box you have to fill in with letters
before you can post. (Not sure of the name),

CAPTCHA (Completely Automated Public Turing test
to tell Computers and Humans Apart)

I went and had a look at:
http://en.wikipedia.org/wiki/Captcha
as I have CAPTCHA on my web site contact form, but wondered what the letters really meant, and see Alan Turing gets a mention.

But, have a look at the third series of alpha-numeric pictures on the above page. Maybe I am getting old, but some of these are impossible to read, and when they decide to enhance them with back ground drawings, well, how does a human get to actually contact anyone in future?

Best learn how to read them or you may be stuck.
You could always revert to snail mail.

I would find a mathematical question a lot easier, even if it was 3 or 4 levels of operations, with decimal point answers.

I've got an idea on my brain's back burner - to do something much like
that, but instead of distorted letters, it would show a picture of a
random animal - really obvious ones, like "cat" and "dog" and "lion"
and "horse" and so on, and say, "enter the N-letter name of this animal",
and give them a hint like the first letter:

[pic of lion] Please enter the 4-letter name etc: [L___]

It would fail to a fairly simple keyword detection and dictionary attack. Computers are also getting pretty good at recognising simple objects in pictures - distortion is about the most robust (ie computationally intensive) defense against automated abuse of mail.

The sheer beauty of CAPTCHA is that with a few exceptions the target pattern can be hidden by distortions from all but the most sophisticated AI programs (which would then take an age to read it) and still be relatively easy for a human. I have seen a few duds too.

Regards,
Martin Brown
** Posted from http://www.teranews.com **
.

Relevant Pages

  • Google and Spam and Captcha.
    ... CAPTCHA (Completely Automated Public Turing test ... to tell Computers and Humans Apart) ... as I have CAPTCHA on my web site contact form, but wondered what the letters really meant, and see Alan Turing gets a mention. ...
    (sci.electronics.design)
  • Re: Google and Spam and Captcha.
    ... CAPTCHA (Completely Automated Public Turing test ... to tell Computers and Humans Apart) ... letters really meant, and see Alan Turing gets a mention. ...
    (sci.electronics.design)
  • Re: Google and Spam and Captcha.
    ... CAPTCHA (Completely Automated Public Turing test ... to tell Computers and Humans Apart) ... letters really meant, and see Alan Turing gets a mention. ...
    (sci.electronics.design)
  • Re: Pavlovs dogsteins. Re: Fresh Fiskiness
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    ... Google captcha? ... recently warned me that Calculator was trying to ... test to tell Computers and Humans Apart". ... "CAPTCHA tests are based on open problems in artificial intelligence ...
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