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How Would You Design a Captcha for the Deaf-Blind? 99

kesuki asks: "Right now, the state of the art captcha only works for the visually-abled. Some people are trying to start a grass roots opposition to catcha using existing anti-discrimination laws. However, without any captcha at all, spammers would have a field day. Audio captcha would work for the blind, of course, but they still leave out the deaf-blind using brail interpreters to use their computers and navigate the web. What system of captcha can you dream up that would work for the deaf-blind?"
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How Would You Design a Captcha for the Deaf-Blind?

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  • My 2 cents... (Score:3, Insightful)

    by markild ( 862998 ) on Wednesday December 21, 2005 @06:19PM (#14312670)
    I'm sorry to say this, but this sounds like a extremely narrow question.

    For instance: What website with content for deaf-blind (_only_ text) would require registration to retrieve such information?
    Yeah, I know (from TFA) some blogs have captcha registration, but do they require registration?

    Anywho, my answer. Hire an assistant/interpreter. That would probably be much cheaper, and much easier.
    Either that, or I would send the authors of the web-site a e-mail, and if it's not a heavy traffic one, they could probably help you out, even though you can't read the captcha.
    • Anywho, my answer. Hire an assistant/interpreter. That would probably be much cheaper, and much easier.

      The question isn't what makes sense, it's how you would deal with a law that ties your hands. (If you take Adrian Trenholm's word that his country regulates the accessibility of blogs.)

    • I'm sorry to say this, but this sounds like a extremely narrow question.

      23000 deafblind people in the UK alone. [rnid.org.uk]

      Hire an assistant/interpreter. That would probably be much cheaper, and much easier.

      What the hell are you smoking?
      • Let's look at it this way.
        I probably register on far more sites online than the regular guy. Still I can't remember the last time I had to use captcha (maybe two or three times the last year).
        How many of the 23K do you think _regularly_ has to interpret one? Every single one, every single day?

        Now who's smoking?
        • There was one point where for me every slashdot post required a captcha.
          • It's called posting without being logged in.
            • No I was logged in, but I still had to use captcha. It might've been because they greylisted my IP or something like that. It went away after a while.
              • I'm sorry, that's not exactly what I meant.

                As far as I understand, it used to be that one used the captcha if they had low karma, but it's not like that anymore.

                The point of my post, which I guess seems rather unclear now that I reread it, is that *now* a captcha is still required, but if you aren't logged in.

                I apologize for the confusion.

      • 23000 deafblind people in the UK alone.

        Actually, "There are about 23,000 deafblind people in the UK. Some will be totally deaf and totally blind, while many others will have some hearing and/or vision."

        From my reading of the link, I get the sense that many deafblind people can be helped by equipment to help people who are only deaf or blind.

        "Deafblind people can get equipment to help them live independently. These include alarm clocks with large raised numbers, computer packages that display text on
      • Thats 0.04% of the UK population (56million). Is doing a lot of work specifically for this minority actually going to pay off?
    • Re:My 2 cents... (Score:3, Informative)

      by kesuki ( 321456 )
      What website with content for deaf-blind (_only_ text) would require registration to retrieve such information?

      I was thinking of such uncommon sites as slashdot.org (low karma users had manditory captchas to post, and they still may have random/anti flood ones) or perhaps Google.com's blogger.com which requires a captcha for every comment. I was also thiking of e-mail signups at yahoo.com hotmail.com mail.com etc. Anyone at anytime could loose both their hearing and their vision, either from infection, o
    • Any webmail service would require registration to retrieve the information it displays - the email sent to you.

      And if you are deaf/blind, email is pretty much the only way you can communicate.
    • You can't find an example? Ever use Slashdot? You need to pass a captcha to post anonymously and/or open an account. Don't tell me you come here to look at the icons...
  • Had a similar idea (Score:3, Informative)

    by Nos. ( 179609 ) <andrew@@@thekerrs...ca> on Wednesday December 21, 2005 @06:21PM (#14312683) Homepage

    Okay, this is a shameless plug, but I started work sometime ago on http://aomis.net/ [aomis.net] (I won't href it). Anyways, the idea was instead of CAPTCHA, which I don't really like, I thought why not let users identify different types of media. Now, I hadn't considered folks who were blind and deaf, but I did build the system to handle multiple types of media, like pictures and audio, which would help folks that are blind or deaf, but not both.

    Now, the sites not quite ready, I'm still playing with a few things, like getting more media into it, but I'll have to watch this Ask Slashdot for good ideas on how to handle those who are blind and deaf.

    • That's a neat idea. Sounds like more fun than the current CAPTCHAs. ;) Not sure how well it could be applied to audio though - famous songs? Movie quotes? Animal sounds? I guess simple sentence transcription would do it, but that's pretty much what standard audio CAPTCHAs would do.
  • A math question (Score:3, Interesting)

    by DynaSoar ( 714234 ) * on Wednesday December 21, 2005 @06:23PM (#14312702) Journal
    All in words, no numerals:
    Challenge (example): "seven times three"
    Response "twenty one"
    • The problem with this is, it would take anyone (including me) about three minutes to write a parser for that.

      It has to be flawed, and it has to be dynamic.
      • Re:A math question (Score:5, Insightful)

        by Scorchio ( 177053 ) on Wednesday December 21, 2005 @06:49PM (#14312907)
        The trick is to add enough variations to make automated parsing difficult. Plus, throw a few word based questions in there...

        What is 6 minus the sum of 2 and 2?
        Is 2 higher than eighteen?
        Which of the following is an animal? Brick, horse, factory, sky.
        Type four letter Q's then the letter N.
        How many P's in pineapple? ...and so on. Not so easy to write an automated parser if there's a few thousand variations to cope with.
        • Interesting questions. Interesting approach.
        • Not so easy to write an automated parser if there's a few thousand variations to cope with.

          How are you creating the variations?

          Your scheme fails because the level of effort to create a variation or to defeat one is about the same.

          Whatever re-wording algorithm you write, will be subject to a similar "solving" algorithm, and the system doesn't provide any order of magnitude advantages for the goods guys like crypto does.

          A potential solution might be to ask questions that a computer simply cannot answer "Will
          • A potential solution might be to ask questions that a computer simply cannot answer "Will this code halt?"

            The halting problem is only unsolvable in general; that is, no computer can decide it for every conceivable piece of code. But it's quite possible, often trivial, in the vast majority of cases. Computers would probably do at least as well as people on that captcha.

      • so it should be more like this?

        Challenge (example): 53v3n +1m35 +hr33
        Response +w3n+y 1!1!!1!!!!!!

    • Re:A math question (Score:3, Interesting)

      by BrynM ( 217883 ) *
      Searching for word names of numbers is almost as easy as solving the math. I have a few standard functions in my code library that translate words to numbers and back in at least three languages. I can bet most other programmers do too. Good idea, but some random mis-spellings of the words would make it better. For example:
      Challenge: "sevn t1mes thrree"
      Response: "21"
      Humans are good at figuring out missspelled words and what they are. I guess someone could use a spell check library, but massaging it to hac
      • I noticed a typo in the mis-spell example. The response should have been "UTSS". Sorry about that... damned phone calls while I'm "busy" posting.
      • The idea of using the misspelled words will not work for someone using a screen reader.

        The above example would read something like:
        "sev en tee one mess tea h are ree"

        Try reading it out loud and see if it makes any sense to you. Jumbled together from a poor computer generated voice it might sound like:
        "73 messy tea area"

        I can't say I have a solution, just that this one might not work well.
        • The idea of using the misspelled words will not work for someone using a screen reader.
          Good point. There must be some way to get a screen reader to read off letters tough. That would work for the mis-spelling only example. "O n i a d P t a t e g" maybe? ...gotta download a screen reader to test...
      • Re:A math question (Score:3, Informative)

        by Blkdeath ( 530393 )

        Maybe something that mis-spells words in the first place might work. Say, provide the wrong letters: Challenge: "Oniad Ptateg" (hint: America ) Response: "NTSS"

        Since I'm still trying to figure out what you mean (even with the spelling correction), that wouldn't make a good test. You'd eliminate those who can't make an immediate distinction. The idea behind such tests is to show a human something that they can immediately associate and give the correct answer. Giving out word problems and puzzles will on

    • You rule out 67% of the population right there.
    • just pipe it to google and your captcha is defeated

      http://www.google.com/search?hl=en&q=seven+times+t hree&btnG=Google+Search [google.com]

      seven times three = twenty-one

    • What if they enter in 3333333?
  • How about... (Score:2, Insightful)

    by Bin_jammin ( 684517 )
    a personal assistant? I hate to sound harsh, but I don't understand how these people can function in a world that at a bare minimum seems to require one or the other sense (sight vs. hearing), and the absense of both means perhaps these people are going to be left behind. How much could it possibly cost to have someone help them, I imagine they need help when they leave the house, would an internet nurse be so far fetched?
    • would an internet nurse be so far fetched?

      There are already TTY operators that deaf people have access to through their telephone line and a special device, and this same service can also be accessed over the internet these days. Conceivably, a deaf-blind person that is challenged with a graphical captcha right now just has to go to his TTY operator on the net, using a computer with a braille display, and talk them into going to the site and signing them up. Why not? It's already there, they're there to hel
      • Re:How about... (Score:3, Interesting)

        by Feanturi ( 99866 )
        Ok, I'm replying to my own post, whatever.. Anyway here's something you could try to make: That small dot-matrix display, make it much more useful by developing a less expensive way to make tons of these 3d pixels that don't break down often. Work on that. Make a display that could show an actual VGA output at a low-but-acceptable resolution if you could make a good enough array of pins. Colours could be represented by the heights of the pins: a special driver would be involved to assign incoming colours to
    • Many deaf-blind live and travel alone with only occasional assistance. It's not easy, but it can be done.
  • If one is trying to make one that can be read through brail, I would say, that it couldn't be done. Captcha designed for it probably would be nothing like captcha at all.

    However, not being deaf/blind myself my view is limited. The real people to ask are the deaf and blind since they would probably have far more creative solution for checking user validity using the input/output devices that they are accustomed to using.
  • From a practical standpoint, the number of deaf and blind people (people of both conditions) is very small, the traffic from spam is probably far greater than that of legitimate users blocked. I can expect that most systems to allow using vision or sound for CAPCHAS.

    I'd hate to simply block people off, but I understand why people that use it.

    I would expect thtat the anti-discriminatory laws probably won't do jack for individual site administrators.

    disclosure: I am partially deaf but see 20/20 with correcti
  • There have been ideas to have email "stamps" where the sender "pays" by working out something that is easy to check, but difficult to compute, like factorising something. Wouldn't that work just as well for this? The downside is that it needs the browser to know about it to be completely transparent to the end-user.

    On the other hand, CAPTCHAs are already broken [wikipedia.org], so this is only suitable for deterring the most stupid spammers in the first place.

  • by Lord Bitman ( 95493 ) on Wednesday December 21, 2005 @06:43PM (#14312860) Homepage
    There have already been captchas designed which show a semi-randomly created arrangement, and ask the user to solve something based on the image. (I dont remember the example, but someone untrusted in my head is saying "where is the person in relation to the bowl?"). Couldnt be too hard to construct a sentence the way you construct an image. Note that the image doesnt need to make sense, it just needs to have its basic components be recognizeable by a person.

    But then someone will complain "By using sentences, you're blocking out all the blind deaf non-native-english-speakers, who can't determine the subtleties of meaning any better than a computer!"
    Eventually there has to be a cut-off point.

    Yes, I am talking about trying to get a computer to randomly generate riddles.
  • Easy (Score:3, Interesting)

    by epsalon ( 518482 ) * <slash@alon.wox.org> on Wednesday December 21, 2005 @06:45PM (#14312875) Homepage Journal
    Have a simple form for the deaf-blind. Add a field asking to explain your condition in your own words. The form gets read by real people who may send a follow-up e-mail asking for a reply. You can easily detect if you're talking to a computer. You can make the form only visible to text-based browsers. As this will not work for spamming, few will fill in the form.
    • Or you could just have an 800 number option for people who choose to skip the captcha.

      If you are having difficulty with this image call 18XX-XXX-XXXX. Problem solved. The Telephone is the wheelchair ramp to the internet.
    • I'm currently designing an application where I honestly think Captchas are needed. I'm also doing email address verification as well. After thinking about this for awhile, I really don't know what to do (and I'm not the Story Parent).

      At first, I thought the personal approach was best but there are a few flaws with this reasoning.

      1. Anyone with programming experience can customize several responses and randomly send them out. If they're real creative, they can tell the program to pick from a list of sentence
  • by robla ( 4860 ) * on Wednesday December 21, 2005 @06:47PM (#14312884) Homepage Journal
    If there were someone running an OpenID site [openid.net] that had an accessible but spammer-unfriendly login mechanism, that site could serve as an alternative login for visually-impaired users. That admittedly just punts the issue, but the nice thing about that solution is that if there was a trusted site that most blind people would feel comfortable registering with, that site could vet the visually impaired. The OpenID solution wouldn't have to be limited to the blind, but that seems the easiest bootstrapping mechanism, as the blind are probably more motivated to promote/use something like OpenID than people who are perfectly happy with Captcha.


  • How about (Score:3, Interesting)

    by Landak ( 798221 ) <Landak@gmail.com> on Wednesday December 21, 2005 @06:48PM (#14312897) Homepage
    "If you cannot view this Captcha, please email foo@bar.com [spam assasin'd, of course], or call 0800-1234-567"
  • It wouldn't be that hard to write a program that wrote little reading comprehension tests that would be very hard for a spammer to solve.
  • A phone number (Score:4, Insightful)

    by hoggoth ( 414195 ) on Wednesday December 21, 2005 @06:55PM (#14312939) Journal
    Pretty simple really. For the incredibly small percentage of the population that is both deaf and blind you supply a phone number to a braille tele-type service (whatever the standard is for deaf-blind communications). You hire one person to handle all the calls, and give him something else to do while he's waiting for the teletype to ring.
    Perhaps do this as a service for ALL interested web sites to share.

    Sometimes we geeks forget that everthing doesn't have to be solved by high-tech wizardry.
    • so what happens when spambots start calling that number and trying to convince the operator to give them accounts?
      • > so what happens when spambots start calling that number and trying to convince the operator to give them accounts?

        They will fail the simple Turing test given by any operator who asks "how's the weather over there" or "can you believe that game last night?"

        It's a person. A human being. How do you suppose a bot is going to do this?

        REGISTERBOT: "Hello. I would like to sign up for an account."
        OPERATOR: "Ok, No problem. What's your name?"
        REGISTERBOT: "John Doe."
        OPERATOR: "Hey, my in-laws are named Doe, are
    • Captchas work by creating something that is easier for a human to decipher than a machine. An analog on a Braille display might be to keep changing the keys in patterns where the end users can 'feel' the phrase stand out against the 'noise.' To the bot it will look like a random string or characters, but as the words repeat, a few letters here, a few letters there, eventually the blind-deaf user will realize the hidden content.
  • Entire avoidance (Score:3, Interesting)

    by irc.goatse.cx troll ( 593289 ) on Wednesday December 21, 2005 @07:03PM (#14312996) Journal
    "If you can not see/hear this, please email an admin for assistance".

    Then when you get a request, manually assist them assuming they send a nice enough email. Get 500 email requests? mass delete.

    Don't forget captchas are to prevent repetitive automated signups, not just a single signup.
  • What about these?

    Choose the correct answer:

    Cats have _____ (a) fur (b) hair (c-d) other bogus choices

    Ice is made of ________ (a) water (b) purple (c) grass (d) trees

    Just use things that are common knowledge to humans but that'd be tough for computers to figure out. Of course, CAPTCHA systems are always vulnerable (the attacker can just pass through the challenge to the victim), but they provide more than zero security.
    • Multiple choice is no good because an automated bot can always guess 'a' (or just randomly) and be right on average 1/4th of the time. Even if a bot can only guess correctly 1% of the time, the system is broken because they can make up for all the bad guesses with volume, volume, volume.

      Having said all of that, I hate the idea of CAPTCHAS and really hate the ones that go so overboard that I can barely solve them myself.

      • Yea, there have been a few times where I've been frustrated at the quality of the Captchas since people think that they need to have a massive amount of lines through the text...
    • someone has already pointed out the problem of multiple choice but even if you find a way arround that you still have the problem that if you can't autogenerate tests the spammer can just compile a complete test list.

    • The second question run through Google:

      Alternative Hits
      Water 28,700,000
      Purple 3,770,000
      Grass 4,560,000
      Trees 8,390,000

      On the first question a simple query actually returned more hits for hair than fur. If you put the question in quotation marks you get the results 1,040 to 579 in favour of "fur".

      There are actually people doing research on giving programs "common sense" like this by doing clever things with electronically available information.
  • I wouldn't (Score:3, Informative)

    by aziegler ( 201013 ) <halostatue@g3.14159mail.com minus pi> on Wednesday December 21, 2005 @07:32PM (#14313192) Homepage
    They're broken, anyway. Try something else, like a two-phase signup process.
  • blogs.sun.com uses quite simple "Answer this simple math question: X + Y = [...]" textboxes and it seems to date to be quite effective. If spammers evolve, just add more language entropy to the questions (ie phrase the question in woolier language, "What is X added to Y?" "The addition of X to Y is?" "If you have X and Y apples, how many do you have altogether?", etc). You can use other types of questions too obviously.

    Works perfectly with screen-readers.

  • by zoeblade ( 600058 ) on Wednesday December 21, 2005 @08:01PM (#14313387) Homepage

    So, if I understand this right, you need a computer to be able to randomly generate a question and corresponding answer from scratch (pulling it out of a database would presumably just lead to the spammers cataloguing all of the question componenets), but on the other hand, you need a computer to not be able to work out the answer when given just the question.

    My best idea is to get it to generate long-winded English sentences along the lines of this:

    Please enter any five letters, except that the middle one must be E. Make sure two of the letters are the same.

    It would probably be a lot easier to just have a human being read each post and make sure it's not spam before displaying it publicly though, as is the case with moderated newsgroups.

    At the rate we're headed, it seems like pretty soon Google will be able to whip up a robot that can beat the Turing test or Voight-Kampff empathy test.

  • well, it would require more organization and centralization but if the world's major deafblind organizations got together and issues digital certificates to their members site owners could accept the certificate as an alternate registration and alternate login to bypass the captcha.

    sort of like handicapped parking rather than making all parking spaces accessable to handicapped people we set aside alternative places to park which require a basic form of authentication (tags and stickers) the internet lends
  • Ever taken an IQ test?
    1. A ball is to a circle as a block is to a ______
      • hemisphere
      • dog
      • square
      • onion
    2. Martin is 3 years older than his cousin Oliver. Olivers mom Vanessa is 4 times as old as Oliver, and three times as old as Martin. How old is Vanessa?
    3. Franklin was very found of the sun and of heat. He wanted a square house with a window on each wall, each facing south. Where did he build his house?
      • The north pole
      • The south pole
      • Equator
      • Hawaii

    And so on...

    Of course, this discriminates against users

  • One word: teledildonics!!!
  • The only way we can all be truly equal is for all of us to be only as capable as the least capable among us. Let's get on this.
  • To lazy to check but very recent I saw that during signup you can also have the catchpa spoken out. It was a regular link so a speech to text browser should be able to detect as well the poor sighted.

    Is it secure? Well I suppose both speech and sight can be regonized by software. Just make the sound with background noise that humans have no trouble with but machines do. Same as the visual ones.

    Really the question seems immensly stupid to me. Gee, we got blind people who can't see a piece of text. Oh my go

  • Anyone else notice that they were mis-using CAPTCHA throughout the article. CAPTCHA stands for a turing test (completely automated public Turing test to tell computers and humans apart). They can be discriminatory but not all of them are.
  • I thought that someone once made special mice with a finger tip vibrating pin-pad that would enable someone to feel the screen by moving the mouse around? (I don't imagine that it would be at all easy to read the Captcha text that way, but it might be a start.) Was this a goofy tech that never worked out, or did I imagine it and should I rush to the patent office with my new idea? (Strictly defensive patent, of course... But imagine the new pr0n possibilities for the deaf-blind!)
  • How do you even design a browser for the deaf-blind?

    Seriously, I have no idea. Quick google shows nothing.
  • When I was an undergrad I did my student teaching in the Deaf-Blind unit at Perkins School for the blind, and the normal interface is a multi-line Braille "display" made of small "pins" that would pop up to form the Braille characters. Of those students that would use these devices, they read quite well and normal English would not be a difficulty for them.

    We normally communicated with the students using "tactile" sign language, which is essentially American Sign Language with the "listener's" hands resting
  • I personally just present a simple math problem that's randomly generated, e.g. what is 4 + 8? If the client doesn't get it correctly, then they can't post, create an account, etc. I've yet to encounter a spammer that uses a bot smart enough to answer that sort of question. Of course, this approach leaves out those with really low IQs or who haven't completed first grade, but I think I can live without their comments on my blog.
  • by Hard_Code ( 49548 )
    How do you do ANYTHING for deaf-blind people? This seems to be a much larger, general problem. Signs? Prices? Car horns? Consumer product instructions? The list goes on. It seems simple math or word problems would suffice, but the problem is the IO. How do you get the challenge to and the answer back out of the handicapped person?
    • Computers are IDEAL assitive technology for the deaf-blind. they open up a whole new world for deaf blind individuals, because now they can communicate and interact and be treated just like any other annonymous coward on the internet. there are enough companies making or trying to improve existing technologies, and it's true the deaf-blind are limited to the functionality of a command-line/keyboard shortcut/macro/script based interface, but as many slashdot readers can tell you the power and functionality
  • Add a css style like to a special browser that interpretes to a hardware device for whatever specific disability you are circumventing. Like a <blind> or something.
  • Seriously how many deaf and blind people are there?
    on your registration do this:
    please respond to the following captcha, or if you are unable to respond do to physical handicaps and/or do not have someone to assist you please click "this link."

    this link would send an email requesting registration, the Administrator then checks over the info and either auths them or not.

    Why is this so difficult?

Computers are unreliable, but humans are even more unreliable. Any system which depends on human reliability is unreliable. -- Gilb