Posts Tagged ‘spam’

What are CAPTCHAs?

Thursday July 16th, 2009

A CAPTCHA is a validation code (combination of letters and numbers), which you are asked to enter before submitting information to a website. CAPTCHA is actually an acronym for “Completely Automated Public Turing test to tell Computers and Humans Apart.” CAPTCHAs display an image that people can detect, but computers cannot and it is used to keep malicious computer “bots” and other automated programs from using Web forms.

recaptcha

Actually a good idea, but there’s a lot of time and effort involved in it. Approximately 150.000 hours are spent every day by users around the world trying to decipher CAPTCHAs. Sometimes they use distorted images like wavy letters or a background with a strong pattern, which makes it difficult for humans to read them too. ReCAPTCHA, which we use on motigo, aims not only to make this easier but also to give this lost time a useful purpose.

reCAPTCHA uses real words instead of the code fragments used by conventional CAPTCHAs. The words used by reCAPTCHA are words, which computers could not read when digitalizing a book. So, when you type a reCAPTCHA, you are actually helping to digitalize a book. Read more on the reCAPTCHA website .

Want to use a CAPTCHA on your website? Find out how in Tips&Tricks. For futher informations, please visit http://en.wikipedia.org/wiki/CAPTCHA

Use CAPTCHAs against spam on your website

Thursday July 16th, 2009

Web forms in online shops, forums and guestbooks are often targets of Spam. You can protect yourself from unsolicited comments by using CAPTCHAs on your website. Along with commercial solutions, you will find many free CAPTCHA services on the Internet, such as  captchas.net. Another free and easy to use service is reCAPTCHA.

recaptchanewsletter

On http://recaptcha.net you get a free key for using the service on your website. In order to use reCAPTCHA, you need a public/private API key pair. This key pair helps to prevent an attack where somebody hosts a reCAPTCHA on their website, collects answers from their visitors and submits the answers to your site.

recaptcha3

To use reCAPTCHA, you only have to add a few lines of code to your website. For detailed instructions on using reCAPTCHA please visit reCAPTCHA’s website.