What is CAPTCHA?

Posted on April 11, 2008
Filed Under Software |

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I know what you are thinking when you glanced at the acronym. You must have said to yourself, not another acronym! When will computer enthusiasts ever stop inventing acronyms to complicate things for people who are already confused by the excessive overload of information from the www. Mind you, CAPTCHA is not a new acronym and if you have to learn one acronym, I suggest you learn about CAPTCHA. I say this because if you are a blogger, you will want to know about CAPTCHA. You must know about CAPTCHA. It will help you.

What is CAPTCHA?

CAPTCHA is the acronym for “Completedly Automated Public Turing test to tell computers and Humans Apart”. CAPTCHA is a program that protects websites from bots by generating and grading tests that humans can pass but current computer programs cannot.

* The term CAPTCHA was coined in 2000 Luis von Ahn, Manuel Blum, Nicholas J. Hopper (all of Carnegie Mellon University), and John Langford (then of IBM).

Why CAPTCHA should not be ignored?

1) If you have a blog or website and encourage comment, you are bound to get a lot of comment spam. How do you control or eradicate commemt spam? In WordPress we have Akismet, a comment spam fighter with a very good cause but what if you are not using WordPress. What if you are using some other blogging platform? Installing CAPTCHA will help reduce comment spam.

2) Bots are not your friend. They are programs that will happily scrap your site for your content without you knowing it. It is not difficult to use a bot and set up the bot to happily scrap your blog and leave traces of spam comment. With some knowledge of site scrapping, anyone can find an open source bot program online, modify it and send it out to spam the world wide web. CAPTCHA steps in and puts a stop to this and makes your life as a webmaster less stressful. It takes the stress off combating spam.

Where to download free CAPTCHA plugin?
You can download free CAPTCHA code from http://www.captcha.net/captchas/ The following are available for installation on your blog and website.

PHP CAPTCHA Plugin

MEdiaWiki CAPTCHA Plugin

WordPress CAPTCHA Plugin

ASP.NET CAPTCHA Plugin

Others

CAPTCHA implementation on StumbleUpon
Read why StumbleUpon implemented CAPTCHA: http://blogaboutyourblog.com/2008/03/13/stumbleupon-now-using-captcha-for-reviews/

StumbleUpon CAPTCHA