

Ask HN: What ideas do you have for creating the ideal CAPTCHA? - solipsist

CAPTCHA - Completely Automated Public Turing test to tell Computers and Humans Apart<p>An ideal CAPTCHA would have the following:<p><pre><code>   1. Human Verification - Only be able to completed by humans
   2. Additional Use     - Example: reCAPTCHA
</code></pre>
Human verification has to include something that can be done easily and universally by all humans (including disabled people), but be impossible for any machine to do. An additional use is simply a bonus, as it converts the time spent on the CAPTCHA into something useful.<p>We have a lot of different CAPTCHA's out there already and the most common one is reCAPTCHA. However, we should <i>think outside the box</i> in order to leverage other skill sets that we have that computers don't.<p>Personally, I find this area very interesting with many possibilities. What do you think?<p>Examples:<p><pre><code>   http://www.google.com/recaptcha
   http://blogoscoped.com/archive/2010-05-03-n58.html
   http://www.arraystudio.com/as-workshop/the-captcha-alternatives.html
   http://www.evengrounds.com/developers/alternatives-to-captcha
   http://onlineaspect.com/2010/07/02/why-you-should-never-use-a-captcha/</code></pre>
======
Athtar
Microsoft Research has a project asking users to identify images of cats and
dogs. It's supposedly harder for computers to solve compared to traditional
CAPTCHA mechanisms.

Link: [http://research.microsoft.com/en-
us/um/redmond/projects/asir...](http://research.microsoft.com/en-
us/um/redmond/projects/asirra/)

------
damoncali
The coolest one I've seen (I forget where, unfortunately) presented the user
with two faces and asked them to pick the more attractive one.

------
bartonfink
Voight-Kampff.

