# How to check for a real person?

**URL:** <https://www.ruby-forum.com/t/how-to-check-for-a-real-person/163365>\
**Category:** Rails\
**Created:** [March 19, 2009, 4:51pm UTC](https://www.ruby-forum.com/t/how-to-check-for-a-real-person/163365 "2009-03-19T16:51:45Z")\
**Posts on this page:** 4\
**Page:** 1

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**Author:** ![sultan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/aeb1de/32.png) [@sultan](https://www.ruby-forum.com/u/sultan)\
**Post date:** [March 19, 2009, 4:51pm UTC](https://www.ruby-forum.com/t/how-to-check-for-a-real-person/163365/1 "2009-03-19T16:51:45Z")

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Some sites have some checks to make sure that the data is being sent  
by a real person.  
Something like this:

See this code? [there is a image here with random letters and  
numbers]  
Re-type it here [you have to enter exactly what is show above]

Any help will be appreciated.

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**Author:** ![sultan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/aeb1de/32.png) [@sultan](https://www.ruby-forum.com/u/sultan)\
**Post date:** [March 19, 2009, 4:55pm UTC](https://www.ruby-forum.com/t/how-to-check-for-a-real-person/163365/2 "2009-03-19T16:55:23Z")

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It’s called Captcha

> **[CAPTCHA](https://en.wikipedia.org/wiki/Captcha)**
>
> A CAPTCHA (/ˈkæp.tʃə/ KAP-chə, a contrived acronym for "Completely Automated Public Turing test to tell Computers and Humans Apart") is a type of challenge–response test used in computing to determine whether the user is human.
> The term was coined in 2003 by Luis von Ahn, Manuel Blum, Nicholas J. Hopper, and John Langford. The most common type of CAPTCHA (displayed as Version 1.0\[clarification needed\]) was first invented in 1997 by two groups working in parallel. This form of CAPTCHA requires...

Here’s 10 examples (reCaptcha probably being the most common):

[http://woork.blogspot.com/2009/02/10-free-captcha-scripts-and-services.html](http://woork.blogspot.com/2009/02/10-free-captcha-scripts-and-services.html)

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**Author:** ![sultan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/aeb1de/32.png) [@sultan](https://www.ruby-forum.com/u/sultan)\
**Post date:** [March 19, 2009, 8:02pm UTC](https://www.ruby-forum.com/t/how-to-check-for-a-real-person/163365/3 "2009-03-19T20:02:38Z")

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Thanks Lee, this helps me a lot.

On Mar 19, 9:55 am, Lee S. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid)

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**Author:** ![sultan](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/s/aeb1de/32.png) [@sultan](https://www.ruby-forum.com/u/sultan)\
**Post date:** [March 19, 2009, 10:09pm UTC](https://www.ruby-forum.com/t/how-to-check-for-a-real-person/163365/4 "2009-03-19T22:09:59Z")

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-OR-

implement a negative captcha! I kind of like this idea.

> **[\[WebAppSec\] The idea of negative CAPTCHAs - Ruby on Rails Security Project](https://rorsecurity.info/journal/2008/4/4/webappsec-the-idea-of-negative-captchas.html)**
>
> Spam and automatic submitters really are a problem. One idea to defend this are CAPTCHAs. CAPTCHAs are noisy images and the user (usually) has to recognize the text in the image and enter it in a field. Although some weak algorithms are already...