On Tue, June 12, 2007 2:06 pm, Daniel Brown wrote: > Okay, here's something I whipped up today: > > http://pilotpig.com/captcha/index.php > > Works pretty well, but keep in mind that it's in the very early > stages. I randomized the position and size to assist in throwing off > Turing detection, and added color not only to screw with the > color-detection schemes, but also in case it overlays the target > bubble. It's 600x400, so that's 240,000 potential spots to click, > with random size, location, and area coordinates thrown in the mix. Trivial to crack... Edge detect the circle colors. Edge detect the text well enough to know what color to choose. Not that it's a VERY limited set of dictionary words to match against. Game Over. I also note two facts: 1. The color to be picked is always the top-most circle, so any circle "behind" another circle can be immediately discarded. 2. If #1 is not true, a human could "fail" because you could easily have one circle completely obscure the correct answer circle. http://php.net/imagecolorat This would take maybe an hour to hack up. Try it yourself and see. You'll learn more by cracking your own CAPTCHA than you will by trying to come up with another one. -- Some people have a "gift" link here. Know what I want? I want you to buy a CD from some indie artist. http://cdbaby.com/browse/from/lynch Yeah, I get a buck. So? -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
