I used to think Captcha’s just a waste of time but with the recent spam bot attacks on my site where I received more than 150 spam comments in just two days, I decided to put one in place to prevent these robots from consuming my server resources and having a commenting spree here at GEORYL.
If you’re a frequent commenter, you probably notice that you are now required to enter a Captcha code before submitting your comments. Sorry that I have to bother you with this additional step (don’t worry, I set the difficulty level to easy) but I needed a captcha to make sure that comments being left in my blog are not generated by a computer.
According to Wikipedia, a Captcha’ (pronounced /ˈkæptʃə/) is a type of challenge-response test used in computing to ensure that the response is not generated by a computer.
The process usually involves one computer (a server) asking a user to complete a simple test which the computer is able to generate and grade. Because other computers are unable to solve the CAPTCHA, any user entering a correct solution is presumed to be human.
It is sometimes described as a reverse Turing test, because it is administered by a machine and targeted to a human, in contrast to the standard Turing test that is typically administered by a human and targeted to a machine.
A common type of CAPTCHA requires the user to type letters or digits from a distorted image that appears on the screen – which is what I’m using right now here at GEORYL.
The term “CAPTCHA” is based upon the word “capture”. It was coined in 2000 by Luis von Ahn, Manuel Blum, Nicholas J. Hopper, and John Langford as an acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart.”
Do you also require a Captcha code from your commenters? How do you deal with spam bots and robot commenters?