This guide will explain what CAPTCHA is and what it is used for.
What is CAPTCHA?
A CAPTCHA is a test to determine whether the user is a computer or a human. The most common type of CAPTCHA is an image of obscured letters or numbers displayed in a box. A user must type the sequence correctly before accessing website or submit data. As automated bots are not able to read these images, they are prevented from misusing the website’s resources.
The following image is an example of a common type of CAPTCHA:
You should consider adding CAPTCHA protection to your website if it has any of the following:
● Surveys or polls.
● Pages that accept file uploads or downloads by users.
● Any other pages that accept user-submitted data.
● Forms that process user-submitted data, including e-mail forms, comment forms, and registration forms.
Following are some of the numerous methods for implementing CAPTCHA for PHP.
● Google provides the reCAPTCHA service. For general information about reCAPTCHA, please visit http://www.google.com/recaptcha. For specific information about implementing reCAPTCHA with PHP, please visit https://developers.google.com/recaptcha/intro
● The Securimage script enables you to easily add PHP-based CAPTCHAs to a website. For more information, please visit https://www.phpcaptcha.org