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Posts Tagged ‘OCR’

Has Captcha been broken?

Friday, November 30th, 2007

I noticed this post at the site Coding Horror. It’s mostly a site for programmers griping about each other, but this one may be of general interest as well as something for the AI community.

If you have been on the web at all, you have probably had to type in some variant of a Captcha security code developed by the whizzes at Carnegie Mellon. (Make a comment on this post if you want to see one in action.) The whole point of it is to defeat programs that will read a security code in the actual html and enter it automatically. Also, they are designed to defeat programs that would take an image of the page (or the Captcha sequence itself) and use OCR (optical character recognition) techniques to detect what characters are being used.

The post at Coding Horror refers to an article from the Wall Street Journal about how Ticketmasteris having problems with bots and scalpers. The problem seems to be that the variant of Captcha that Ticketmaster is using is just not good enough. The solutions for theirs, and many others’, is being sold by companies. However, Captcha algorithms such as those used by Google, Hotmail and Yahoo are “unbreakable”. (Notice that no financial sites are listed?!?)
Anyway, interesting read on how humans can still defeat computers at some tasks. I suppose Alan Turing would be smirking at the attempts.
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