[ Features | Screenshots | Instructions | Download | History | Links ]
{ PHP / Personal Project / January 2008}

This simple to use PHP CAPTCHA Class uses a basic math problem (converted to word form) instead of the normal repeat the letters/numbers concept.

I came up with this interesting CAPTCHA (among other terrible ones) with Adam Rua when we were working on our Senior Project, SHUGamer.com. Originally the image was a lot larger 250x250px and contained messages like “Answer using only numbers.” However, in 2009, I modified the image to be smaller to fit better in my Graduate Project, AreYouAG33k.com. And finally, I recently condensed the various functions into one solid class for anyone to use.

Features

Displays a 250px by 50px image using GD (built into most versions of PHP) with white background, randomly colored polygon, various scattered lines, and a mathematical word problem. No class instances need to be created as it uses Static calls.

Screenshots

Instructions

First, include the Captcha class and start the session (as they are required)

Second, you need to generate a unique CAPTCHA id

Third, display the CAPTCHA associated with this id

Finally, verify the user’s input with the id

History

• 9 April 2010 – v14 – First Public Release

Download

• PHP Source and Example (v14) – 4kb
  • md5: 7D53F351C6B119DDEF08D1220DFB8FED
  • sha1: 81CF1355BCA5AB299C81B573875FC2DD3E1E6ABC

Links/Resources

• Wikipedia – CAPTCHA