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How robots and spiders are causing issues, how to stop them. We can also talk about Completely Automated Public Turing Test To Tell Computers And Humans Apart - their use, their compliance issues, porn proxies, PWNtcha and other ways to defeat them. 
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What about this Captcha?
Date: June 02, 2008 06:04PM

This (TASvideos) one seems kinda interesting, combining text overlayed on a image, with a random pick the X code with the Y color...

It looks like it could be defeated with a special reader though...

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Re: What about this Captcha?
Date: June 02, 2008 06:55PM

Not very user friendly though. It said for me to type in the 3rd red code. 3rd from the top, left, right, bottom? Not to mention the actual image is very weak, having an OCR take apart each code and put into array with color wouldn't be the hardest thing in the world for someone who wanted to defeat it.

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Re: What about this Captcha?
Posted by: istari
Date: June 04, 2008 08:18PM

That's a really bad CAPTCHA, actually: the instructions change from one CAPTCHA to the other, but they are always in clear text, so a robot can easily read them before starting. After that it's a matter of filtering everything that's not the right color, and finding the positions of the different pieces of code (this you can do adapting the functions you usually use to detect letters in normal CAPTCHAs). Then you can read the codes with generic OCR functions (because they're not distorted at all), and feed the correct one to the form.

All in all, it'd take just a few minutes to adapt a CAPTCHA solver for this task, so I don't think they'll stop anyone but the newbies...

It's a good concept though: create more possibilities with the instructions, distort the codes, randomize the colors, use a background with lots of colors, and you'll get a rather strong CAPTCHA with the added bonus that it's not the usual format (and this will put off a lot of people). I'd like to see where this goes...

Edited 1 time(s). Last edit at 06/04/2008 08:21PM by istari.

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Re: What about this Captcha?
Posted by: Kyo
Date: August 08, 2008 12:56PM

adding all the stuff mentioned above this post would make it the most annoying captcha ever, though (well right after the rapidshare one with the cats and dogs)

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Re: What about this Captcha?
Posted by: spearfish
Date: October 10, 2008 09:57PM

I actually see this as just another "security through obscurity" type deals. As soon as this gets popular, it'll be broken almost immediately. And if it doesn't get popular? Well then it's not guarding anything very important now is it.

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