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3D-Based CAPTCHAs Become a Reality

Posted by Soulskill on from the is-that-an-e-wait-i-think-it's-a-5-dangit-let-me-in dept.

mateuscb writes "A new way of creating a CAPTCHA using 3D objects has become a reality. The idea was thought up independently by blogger Taylor Hayward and by the folks at YUNiTi.com. 'Similar to Hayward's idea, this new technology relies on our ability to identify objects in 3D instead of using alphanumeric characters. YUNiti's 3D Captcha, however, has three objects in the challenge and extends the list of images to any object, not limiting it to animals as in Hayward's idea. This increases the challenge's level of complication to prevent computers from successfully making the correct guesses.' I, for one, welcome the thought of not having to read more and more complex CAPTCHA. Lately, I've been having a hard time getting CAPTCHA to work the first time."

3 of 192 comments (clear)

  1. Re:Humans can defeat humans by bobetov · · Score: 5, Interesting

    It's much worse than that. Put up a porn site. Use free content. Have a "Solve captcha to get free pics!" blocker.

    Now, grab a captcha you want to break, show to pornaholics, get solution, pass it back to the original site.

    Perfectly unbeatable captcha solving, for virtually free, and totally automated.

    Feh.

    --
    Looking for a Rails developer in Chapel Hill?
  2. Re:Humans can defeat humans by RyoShin · · Score: 4, Interesting

    That's very true. The problem now isn't rendering CAPTCHAs useless, it's doing so by automated means.

    As you said, anything that must be used by humans can be broken by humans. But you still wind up with logistics problems--having the money to pay these people (or, in the case of free porn, the bandwidth and content to keep them interested) and the fact that those people are still limited by their humanity. Even the fastest typist wouldn't be able to complete a form (CAPTCHA aside) as quick as a robot. And, if a robot can break a CAPTCHA, it can fill that out faster than a human, as well.

    So the issue is preventing, or at least slowing down, robots, which can work 24/7 without a break. A variety of things have been done with normal CAPTCHAs to do this: colors, lines, running letters into each other, adding cats and dogs to letters (seriously). This step, once "perfected" and widely adopted, will be a huge leap in stopping these robots. Even if they can be trained to have a copy of the exact 3D models given (which are sure to increase in variety if not types), they still have to take a picture of it from every single angle, which I believe is 359^3 images, and then compare every single one (which is O(x^n) time, where x is the time for one image comparison).

    It's an arm's race, though. Eventually some enterprising hacker will figure out a way for bots to "guesstimate" based on various aspects of an image, and once that solution is sold to the highest bidder we start the war all over again.

  3. They must be Runescape players by peterofoz · · Score: 5, Interesting

    So Jagex's Runescape MMORPG has had this for a couple of years in random events to defeat macros.

    http://www.runescape.com/