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Re: Alternate for Captcha - Need suggestions

From: Colin Lieberman <colinl@yahoo-inc.com>
Date: Thu, 08 May 2008 08:21:38 -0700
Message-ID: <48231A82.7030508@yahoo-inc.com>
To: Priti Rohra <priti.rohra@n-syst.com>
CC: w3c-wai-ig@w3.org

I don't remember where I read it, but I remember an excellent article 
from a year or two ago advocating something like "negative captchas".

The idea was that since bots just fill out every form field on the page, 
so you just need to make an input labeled with "Humans: don't write 
anything in this field or your submission will be rejected", and then 
hide the input and its label with css (probably a good candidate for 
display:none).

Then your form processor just checks to ensure that field is blank. 
Since very few (if any) spam bots have a css parser, they'll just fill 
that field in with something and you can reject them.

I've not seen any implementations of this (that I'm aware of), or read 
any studies on its effectiveness, but it might be something worth 
looking into.

- Colin

Priti Rohra wrote:
>  
> 
> Hi Everyone,
> 
>  
> 
> We have redeveloped a website where the clients emphasis was 
> Accessibility, but finally, due to security, they have added a Code 
> displayed as a captcha. The use of audio captchaís is something I donít 
> want to recommend, since the organizations works in the area of  hearing 
> impairment and also due to the problems with sound quality, etc.
> 
>  
> 
> I am considering suggesting a situation, where the person has to answer 
> a question. If he canít answer, we can give an option to request another 
> question.
> 
> The questions would be picked randomly like
> 
>     * What is the total of 2+2?
>     * What is the color of an apple?
>     * Which is the next day after Friday? 
> 
>  
> 
> Would like some opinions on this.
> 
>  
> 
> *Thanks & Regards,
> Priti Rohra
> Accessibility Consultant & Tester
> Net Systems Informatics (India) Pvt. Ltd.
> Web: www.n-syst.com <http://www.n-syst.com>*
> 
> *www.barrierbreak.com <http://www.barrierbreak.com>*
> 
> *blog: www.barrierbreak.com/blog <http://www.barrierbreak.com/blog>*
> 
> ** 
> 
> ** 
> 
> ** 
> 
Received on Thursday, 8 May 2008 15:24:30 GMT

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