
I believe we have seen this image a lot of time on the web. But what does this script really do is what I am going to discuss. This is a Captcha(Completely Automated Turing Test To Tell Computers and Humans Apart). We all know that this script works as human verification tools for most websites and this helps to identify spam or automated registration, etc. This is really a great tool, you can even listen to the words if you can’t read it well and the best part of this script is it comes for free.
But what we don’t know is that when we type the words displayed from the Captcha image in the text box we already helped digitizing old text. This is no ordinary tool, it is double purpose program and still a very useful one.
According to reCaptcha.net website:
“About 60 million CAPTCHAs are solved by humans around the world every day. In each case, roughly ten seconds of human time are being spent. Individually, that’s not a lot of time, but in aggregate these little puzzles consume more than 150,000 hours of work each day. What if we could make positive use of this human effort? reCAPTCHA does exactly that by channeling the effort spent solving CAPTCHAs online into “reading” books. “
Captchas have several applications for security which are as follows:
Preventing Comment Spam in Blogs.
Protecting Website Registration.
Online Polls.
Preventing Dictionary Attacks.
Search Engine Bots.
Worms and Spam.
So what are you waiting for, include captchas in your websites and be free from spam and help digitize books.