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A comment on I broke textCAPTCHA with Python. Parent comment

Re:I broke textCAPTCHA with Python by gibeson on Friday November 12, 2010 @12:27PM (#1898383)
Sorry, but what do you mean by "knowing all the forms of the questions"? It seems like maybe you mean all that all the questions formatted via one of several formulas like: name <x> of list<a..z>. Which would imply your tool simply identifies the format then applies some specific logic to solve the question. I'm unclear that if that is what you mean, why then do you know all the forms of the questions? Text capture purports over 180 million questions, so isn't it likely you may not have found all the possible formats of the questions? Or perhaps did you know because you have a relationship with the text captcha creator and they provided that info to you. Or better yet, did your comment mean something entirely different.

Just curious, thanks.

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Re:I broke textCAPTCHA with Python by Xk on Friday November 12, 2010 @01:11PM (#1898528)
You are correct, I look for a pattern and apply very very basic logic.

I just got 1,000 questions from the demo page and looked how they were similar. For example, there are many questions of the form "[list of something]: the [ordinal number] [type] is?" so I put that as a rule in the grammar file. I did this for about twenty different types of questions, each of which has three or so different phrasings.

And yes, they may have 180 million questions, but in reality they have only a hundred or so modulo the specific words they pick (for the items in the list, or for the day of the week, or for the letter that the word starts with).

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Re:I broke textCAPTCHA with Python by pyre on Saturday November 13, 2010 @01:05AM (#1900439) 

  > I put that as a rule in the grammar file
What are you using the process the grammar file? What type of grammar?
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Re:I broke textCAPTCHA with Python by Xk on Saturday November 13, 2010 @01:32AM (#1900462)
I wrote a parser generator, so I'm using that.

It's BNF-like.

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