Commercial CAPTCHA breakers for sale(lafdc.com)
lafdc.com
Commercial CAPTCHA breakers for sale
http://www.lafdc.com/captcha/
6 comments
It might (obviously) tend to weed out the color blind, but I think these would be hard to crack:
http://www.toledo-bend.com/colorblind/Ishihara.html
http://www.toledo-bend.com/colorblind/Ishihara.html
Isn't the best way to break captchas to offer "free porn"? Offer free porn, ask them to send you their email, respond to a captcha... send out spam about this free porn and bam...
millions of example images solved.
millions of example images solved.
I'd love to know what's written below.
I can't read Chinese, but I've read some English discussion about how that's done. You know how spam filters 'learn' what is spam and what isn't, this is the same idea. It first splits each letter from the image. Then you create an algorithm that compares the current letter it has to process versus what it has learned. The hard part is that algorithm. You can technically do it with just image matching, but it's far better to programmically teach it rules like "B" has two holes, "7" has two lines, etc. And then you feed the program the first 1000 with proper answers and then you check and see if it's guessing correctly.
Notice how images without proper 'rectangle-size letters' like the Google ones are hard to crack because it's hard for a simple line searching algorithm to find a rectangle box to split the letter. Random lines through the letters, like in Yahoo's also mess with it.
The key is to make letters human readable, but not completely obvious to a captcha reader where one letter ends and one letter begins.
Notice how images without proper 'rectangle-size letters' like the Google ones are hard to crack because it's hard for a simple line searching algorithm to find a rectangle box to split the letter. Random lines through the letters, like in Yahoo's also mess with it.
The key is to make letters human readable, but not completely obvious to a captcha reader where one letter ends and one letter begins.
Is that price in Yuan?
Adding little bits of salt-and-pepper noise, light-colored lines, and other cutesy antics do nothing.
The simple fact is that machines are better at recognizing individual letters and characters than humans are.