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A Vision For a World Free of CAPTCHAs

Posted by Soulskill on from the is-that-an-oh-or-a-zero dept.

An anonymous reader writes "Slate argues that we're going about verifying humans on the Web all wrong: 'As Alan Turing laid out in the 1950 paper that postulated his test, the goal is to determine whether a computer can behave like a human, not perform tasks that a human can. The reason CAPTCHAs have a term limit is that they measure ability, not behavior. ... the random, circuitous way that people interact with Web pages — the scrolling and highlighting and typing and retyping — would be very difficult for a bot to mimic. A system that could capture the way humans interact with forms algorithmically could eventually relieve humans of the need to prove anything altogether.' Seems smart, if an algorithm could actually do that."

12 of 168 comments (clear)

  1. Just a Thought... by ryanleary · · Score: 5, Insightful

    It seems to me that if you can design an algorithm to verify how humans interact with a computer, it should be relatively trivial to engineer an algorithm that mimics this interaction?

    Maybe someone smarter than I could clarify?

    1. Re:Just a Thought... by Nazlfrag · · Score: 5, Insightful

      Using anything other than a human to judge the behaviour puts it outside of the Turing test. So not only does their proposed solution not match the goal they set, it should indeed be defeatable by another algorithm.

    2. Re:Just a Thought... by l3prador · · Score: 4, Insightful

      Yep. If you can characterize the behavior pattern enough to automatically determine that it's "human-like," then you can automatically generate "human-like" behavior. The only way around it that I can see is if there is some sort of asymmetrical information involved, such as the invisible form honeypot mentioned in TFA--the website's creator (and thus the bot-detection script) knows that there is an invisible form present, but it's difficult for a script to see without rendering the site in standards compliant CSS.

    3. Re:Just a Thought... by major_fault · · Score: 5, Insightful

      No algorithm will do. Ultimately the question that must be solved is whether the user is malicious or not. Best possibilities so far are the tried and true invitation system and excluding malicious users from the system. Malicious users are also users who keep including other malicious users. Easily detectable with proper moderation system that needn't be gotten into right here and now.

    4. Re:Just a Thought... by 1+a+bee · · Score: 4, Insightful

      So if I have an algorithm that can verify an integer factorization quickly, it means there must be an algorithm that can factor any integer quickly? How would that work?

      The anonymous poster makes a good counter argument against the idea that the algorithm must be easily defeatible: just because you have an algorithm that detects human behavior does not imply you have an algorithm that emulates the human behavior detected by the original algorithm.

      In fact, there are many, so-called, one-way (correct terminology?) algorithms. So, for example, for a given file, it's easy to compute its MD5; harder to compute a file for a given MD5 (though doable). And of course, the AC's better example which is impossibly hard in reverse for composite numbers made from very large prime factors.

      So no. Labeling the idea flawedbydesign is jumping the gun--logically, speaking.

    5. Re:Just a Thought... by Joce640k · · Score: 4, Interesting

      I disagree. I don't think there's anything terribly un-mimicable about the way humans interact with web pages.

      Besides, have you considered the effect of false positives (which will be many)?

      With a captcha it's a black/white decision and people know why they passed/failed.

      In the world being proposed in the article people will have to sit dejectedly wiggling their mouse while a web page decides if they're human or not based on some unknown criteria. Pass or fail? It's up to the machine.

      After two or three sessions of this people will be running away screaming from your web pages.

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    6. Re:Just a Thought... by jonaskoelker · · Score: 4, Funny

      There's no clear feedback to let a user know *why* he's not being allowed into the system, it's just that the machine doesn't like the look of him.

      So it's like dating? ;)

  2. Not so sure by Misanthrope · · Score: 4, Insightful

    Assuming you could write an algorithm to determine humanistic behavior, it stands to reason that you could write a bot to fool the initial algorithm.

  3. I read something about this by gcnaddict · · Score: 4, Interesting

    I remember reading... I can't remember if it was a post about an algorithm already written or a proposal for an algorithm which would run alongside a CAPTCHA through the entire registration process, but the basic premise was just that: measure the entropy and fluidity of human movement and determine whether or not the user is a bot based on whether or not the user fits typical random human usage patterns.

    I also remember the writer of the post noting that this kind of system would basically stretch the human-unwittingly-answers-CAPTCHA out such that humans would have to do the entire setup process manually instead of just the CAPTCHA, thus defeating the point of automated setup.

    Does anyone have this article? I can remember reading it but I can't find it.

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    1. Re:I read something about this by abolitiontheory · · Score: 4, Insightful

      In addition to this, what about those humans who just happen to fall into the seemingly 'mechanical pattern' that a computer registrant would? I know some parents of friends who very meticulously and methodically fill out forms, reading every box and explanation to ensure that they're inputting the right data.

      Any computer judgment of what is authentically human is in a way a reverse Turing test. It's a computer judging if humans are behaving enough like humans. The problem here is too many degrees of separation: a very specific type of human [engineer] designs a computer to assess the 'humanness' of other humans actions. Any such assessment would be based on certain assumptions and biases about how humans act. It sounds like putting a document through Google translator into another language and then back again, before turning it in for a final grade.

  4. Tech Support by cjfs · · Score: 5, Funny

    I can see it now: "have you tried moving your mouse around randomly?", "how about clicking on a few different parts of the page then making coffee?", "still not working? Try slamming the mouse down several times", "okay, as a last resort click on the tabloid pop-up."

  5. What does it mean to be human? by mcrbids · · Score: 4, Insightful

    It's a lot tougher do define what a human is than it may seem on the surface, and the difference between man and machine will, by definition become more and more blurred until there is no effective difference.

    It's an idea that I've become familiar with esp. aftre reading 'The Singularity is Near' by Ray Kurzweil. As our technology advances, we'll find that our capabilies beyond our technolgy will diminish. Machines have long ago surpassed our running speed (cars/planes/trains) and our ability to farm/grow food (tractors) and our ability to hurl object (guns) and swim (boats) but we've always had the ability to out-think our machines.

    Increasingly, this isn't true.

    We've already shown that SPAM filters are good enough to be more accurate than the people who read the messages. Machines have long been better than people for math-related stuff, keeping track of stuff, and the like, but now we're getting close to the threshhold for image processing and character recognition. It's already true for voice recognition. Captcha is, therefore, doomed to fall eventually as we approach the singularity, and is already pretty weakened. The next question is, therefore simple: what does it mean to be human?

    Remember Lt. Commander Data on Star Trek, trying to be human? It's quaint largely because he/it was a minority on he show, but in reality the machine will outnumber us by a wide margin - they already do!

    So what does it mean to be human?

    If you have a prosthetic leg, are you still human?

    If the leg has a CPU in it, are you still human?

    If the CPU is more powerful than your mind, are you still human?

    If the chip is wired into your mind, are you still human?

    If you use the CPU as though it were part of your mind, are you still human?

    If you have transferred modt of your thinking to the CPU, are you still human?

    If you transferred all your thinking to the CPU and rarely use your 'wet' brain, are you still human?

    If you find th

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