CAPTCHA is an acronym that stands for: Completely Automated Public Turing Test to Tell Computers and Humans Apart. CAPTCHA can be a very handy tool if you collect information about your clients on your web page by forms. If you are not using CAPTCHAs, your website could be accessed by an Internet bot or e-mail spam. You will find that most large websites like PayPal and many e-bank sites use CAPTCHA.
What CAPTCHAs Do
CAPTCHAs determine whether the user accessing the website is a human being or another computer that could be malicious. CAPTCHAs use images that are hard to decipher as the vehicle to figure out which users are actually humans. Images that are stretched or appear to be wobbly can be read by humans, but computers cannot decipher them. Some CAPTCHAs are pictures of animals that a human can easily process, but a computer is unable to analyze.
Why Do You Need a CAPTCHA?
Bots can locate a form that you’ve created and send hundreds of email spam to people using your form. Bots can also fill in your form and establish email accounts, ordering whatever they want using those e-mail accounts set up using your form. In addition, a bot can discover any e-mail address that is included in the HTML used in your form page.
Selecting the Right CAPTCHA for Your Site
Be sure to select images that have text that is randomly distorted and, preferably, uses different fonts within the same image. A good way to confuse computers is to have lines running across the text, since computers cannot distinguish between the random lines and the lines of the font itself. Also make sure to choose a CAPTCHTA that offers an audio alternative for the visually impaired.
You can get a free CAPTCHA at the reCAPTCHA project website. For more information, read Carnegie Mellon University’s article on CAPTCHA.
This article is provided by Patriot Software, Inc., a developer of small business software for American businesses. For more information, visit PatriotSoftware.com.