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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."

16 of 192 comments (clear)

  1. First time? by Tubal-Cain · · Score: 5, Funny

    I've been having a hard time getting CAPTCHA to work the first time.

    And the secondtime . And the third time. And the fourth. And the....

    1. Re:First time? by Idiomatick · · Score: 4, Funny

      You know what that means don't you? You are probably not actually human. The test was designed to weed out 'your' kind. I bet you couldn't even pass a simple Turing test against a 13 year old girl if you can't pass a Captcha. It really is sad when they learn the truth.

    2. Re:First time? by Tubal-Cain · · Score: 5, Funny

      Do you wish that i cant pass a captcha it really is sad what they learn the truth?

    3. Re:First time? by MacTO · · Score: 5, Funny

      I've been having a hard time getting CAPTCHA to work the first time.

      And the secondtime . And the third time. And the fourth. And the....

      I was having trouble too, until I found this awesome piece of software that solves CAPTCHAs for me. It even automatically finds the CAPTCHA image and text entry field so that I don't even have to be bothered by it. ;)

  2. Rationality check by mongrol · · Score: 4, Insightful

    Let's see now. If the spammers and robot makers went outside, done something worthwhile and produced something the world badly needs (food) then this nonsense wouldn't exist, I could surf in peace and the starving millions would live a little longer. The very existence of CAPTCHA's proves the human race is badly in need of a reset.

    1. Re:Rationality check by MWoody · · Score: 5, Insightful

      Such is the way of all intelligent life, though. If you build a maze for a mouse, the rodent may run its course a thousand times to reach the end and its reward. But never be fooled for a second: the mouse likes the cheese, not the maze. If he finds a way to climb over the walls and skip the test entirely, you should be neither surprised nor angry, as the failure is yours.

    2. Re:Rationality check by Idiomatick · · Score: 4, Insightful

      We should spend that effort spammers put out to get useful work done. Re-captcha is a perfect example. How about Google, want a new tagging system for images? It would make image search MUCH more usable. It could also be used to help AI/learning and object recognition. Just set up Captchas to do meaningful boring things that otherwise would not get done. I've no idea why this isn't more widespread.

  3. Humans can defeat humans by Lord+Satri · · Score: 4, Informative

    Interesting, but in a previous /. discussion, I got convinced that there was no perfect captcha, since one can simply pay a group of underpaid workers (e.g. in poor country) to manually solve the captchas...

    --
    Animoog.org
    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 MeanMF · · Score: 5, Funny

      Easy - just make the CAPTCHA so you have to simultaneously type something with both hands.

    3. Re:Humans can defeat humans by forkazoo · · Score: 4, Insightful

      Interesting, but in a previous /. discussion, I got convinced that there was no perfect captcha, since one can simply pay a group of underpaid workers (e.g. in poor country) to manually solve the captchas...

      If it requires actual workers, then it is a perfectly working CAPTCHA. "Completely Automated Public Turing test to tell Computers and Humans Apart." Don't think of it as a way to keep bad posts from your forum, because it isn't. It just tries to increase the likelihood that a human was involved in the process. If you want to limit abuse, getting a guarantee that a human was involved is only one small step in the process.

    4. 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.

    5. Re:Humans can defeat humans by Goaway · · Score: 4, Insightful

      If the spammers have to pay to spam, we've already won.

  4. 4D? Pfft. by artor3 · · Score: 5, Funny

    If you wanna post on my site, you better be prepared to solve the 5D hyper-hyper-cube!

  5. A few common CAPTCHA fallacies by QuoteMstr · · Score: 5, Insightful

    Everyone has a great idea for a CAPTCHA, but very few people know what the hell is really going on. Remember that the machine doesn't need to solve the CAPTCHA every time, that machines are infinitely patient and have huge memories, and that another machine needs to make sure the human gave the right answer!

    Ideas that won't work:

    1. Make clients identify an object from a picture. Machines can't describe objects in pictures: if machines can't describe the picture, how the hell is the CAPTCHA server supposed to verify that the client gave the correct answer? If a human being manually inputs the pictures and acceptable descriptions for each, then another human can program his attacking machine to do the same thing! Having a large, but finite set of pictures doesn't help either since a machine doesn't need to solve the CAPTCHA every time. It can just learn the correct responses without actually understanding the image. ANY APPROACH BASED ON IDENTIFYING A MEMBER OF A FINITE SET DOES NOT WORK AS A CAPTCHA.
    2. As a special case of #2, QUIZZES DO NOT WORK: either the questions are finite and subject to attacker memorization, or the number of patterns for the question is finite, and these patterns can be detected by a machine. (Consider "A train is coming from Denver at X miles per hour..." --- same problem, different coefficients)
    3. Send the client a special program that verifies he's real: if it doesn't work for DRM, it won't work for CAPTCHAs. An attacker can just program his machine to simulate slow typing, slow thinking, or a cross-eyed human being. YOU CANNOT CONTROL THE EXECUTION ENVIRONMENT. No amount of Javascript obfuscation, encryption, or header-checking will make the slightest bit of difference for a determined hacker.
    4. As a special case of #3, TIMING ANALYSIS DOES NOT WORK. Machines can simulate arbitrary delays.
    5. Limiting CAPTCHA-solving attempts by cookie/IP address/etc.: that doesn't work. Attackers don't obey web standards, and have botnets

    Really, it's very easy to think you've come up with a very clever CAPTCHA. When you think that, all you've done is stoked your ego and screwed yourself over. It's the same reason why we don't roll our own cryptography: CAPTCHA-making is a very hard problem, mainly because your problem space must be infinite (to avoid an attacking machine simply memorizing answers), the answers verifiable by a machine, but the problems not solvable by a machine.

    How many questions can be checked by machines but not answered by them?

    Not many; fewer every day. There are no questions that can't be answered by a computer (and which can be answered by a human mind). The Church-Turing thesis has some validity: the human mind is no more powerful than a turing machine, and ultimately, computers and our brains are equivalently computationally. There's nothing a computer can't solve: there are just things we haven't figured out yet.

  6. 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/