Anyone with a blog with any traffic at all, understands that can be super annoying to have to constantly filter and delete comments to get rid of spam. You don’t want your readers to click on a spammer’s website link to be taken to a site you don’t approve of… And you definitely don’t want to publish your email address on your blog, or have a contact form on your site without a captcha form.
Wait, What is captcha?
Technically, it’s “A program or system intended to distinguish human from machine input, typically as a way of thwarting spam and automated extraction of data from websites.”
The cool thing about WordPress, is that there’s a plugin for nearly everything, including captcha. yay!
reCAPTCHA is an anti-spam method originating from Carnegie Mellon University which uses CAPTCHAs in a genius way. Instead of randomly generating useless characters which users grow tired of continuously typing in, risking the possibility that spammers will eventually write sophisticated spam bots which use OCR libraries to read the characters, reCAPTCHA uses a different approach. They effectively kill two birds with one stone.
Digitizing of Books
If you didn’t know, the world is in the process of digitizing books (Even the Library of Congress is too) so that they can last forever as well as become searchable. To digitize the books, Scanners scan the pages of the books resulting in image files. OCR technology is then used to attempt to convert the images to text. Sometimes, however, certain words are illegible to the OCR technology but the good thing is that they know when the technology knows when this happens and can mark the words and put them into a repository. To construct a CAPTCHA, reCAPTCHA takes one of the words from these repositories and couples it with a word they do know, then distorts them some more. When a certain percentage of people type in the same spelling for the unknown word, it is assumed to be correct and sent back to help with the digitization process.
How is this any better?
This effectively means that users who fill in reCAPTCHA forms can feel good knowing they are contributing to the digitizing of books all over the world, so it gives it a purpose. Also, if Industry Standard OCR Scanners can’t read certain words, add to that the fact that they are further distorted before being added to a CAPTCHA, one can be almost certain that Spam Bots won’t be able to read the CAPTCHAs either, this makes it secure.
Many popular websites such as Twitter, Facebook, and even certain Government Websites like the TV Converter Box Coupon site are using reCAPTCHA. It is definitely becoming more and more widespread, and the neat thing is that it is accessible to everyone.
Of course, as it goes in the land of WordPress plugins, there are other options available for captcha! Use what works for you. If you are just adding captcha to a contact form, it may be simpler to use the Fast Secure Contact Form Plugin that has captcha built in as an option. This is the plugin I’ve been currently using the most for contact pages & haven’t had any problems with un-welcomed comments or spam. (Well, I also use Akismet to fight spam, which helps A LOT) 🙂
What do you use to add captcha to your blog? Leave a comment below!