SecurImage Captcha 3.11.1 for J!3 & 4.3.4 for J!4

This Captcha plugin works with any Joomla extension capable of using the Joomla core captcha plugin system. It uses the Securimage PHP CAPTCHA1 script for generating complex images and CAPTCHA codes (including math problems) to protect forms from spam and abuse. It can be easily added into existing forms on your Joomla 2.5 or newer website to provide protection from spam bots. It can run on almost all webservers as long as you have PHP installed, and GD support within PHP. SecurImage does everything from generating the CAPTCHA images to validating the typed code. Audible codes can be streamed to the browser with Flash for the vision impaired.