Note, I'm doing the "puzzle" one - I can't even solve the other one myself >_>
(01-12-2011 04:05 AM)Banalyst Wrote: keycaptcha's "coorect" places (coordinates) are never repeated even for the same captcha;
However, the user/bot is given some fixed objects for where to place the missing parts. Since all the examples I've been given are a 3x3 grid, and there's 3 pieces to place, some simple calculations based on the dimensions of each piece and where whitespace is can tell the bot where the coordinates are.
Once this has been determined there's a total of 6 combinations of where the pieces could go. Or perhaps in a worst case scenario where you have 2x3 stacked pieces, 12 combinations. Even if the bot doesn't try to identify the correct image and just randomly arranges the pieces, they will be correct 16% of the time.
But of course, anyone capable of writing an OCR routine would have little trouble identifying where the correct positions of the pieces are.
(01-12-2011 04:05 AM)Banalyst Wrote: 2)
keycaptchas are shown randomly from a set of many captchas;
3)
captchas are constantly being changed by KeyCAPTCHA devs;
3a)
keycaptcha.com site has online designer for subscribers of "Personal KeyCAPTCHA" (5 USD per month or 20 a year) account to create (any number of) their own captchas from their own images. Hardly someone would bother to create a bot to crack just for one site
If to use pre-built basic set of (ready) keycaptchas, this service is free.
None of this really matters if you consider my point above, unless you change the underlying principle of the puzzle itself.
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