Creating a CAPTCHA with PHP - Improvements and Conclusion

(Page 6 of 6 )

Well that is all there is to CAPTCHA images just a simple writing of text to an image and storing of the text (key). However the captcha I just described how to build is not the best in the world by a long shot. If you're feeling adventurous you could try the following things:

Use a TTF font

Move the lines randomly

Randomly position the text on the image

Rotate the text randomly

Use words instead of that string (ie: have a randomly picked word out of say a file of about 1000)About the Author

Andrew Walsh lives in the UK where he is starting a course of computing and related computer studies at a local college. A programming hobbyist but plans to pursue a career in programming. Currently studying/working with php, mysql, (x)html, css and some limited c++. Sometimes writes code snippets and articles on his personal "development" website at http://walshdev.com/.

DISCLAIMER: The content provided in this article is not warranted or guaranteed by Developer Shed, Inc. The content provided is intended for entertainment and/or educational purposes in order to introduce to the reader key ideas, concepts, and/or product reviews. As such it is incumbent upon the reader to employ real-world tactics for security and implementation of best practices. We are not liable for any negative consequences that may result from implementing any information covered in our articles or tutorials. If this is a hardware review, it is not recommended to open and/or modify your hardware.

Comments On: Creating a CAPTCHA with PHP
   · The Text: As you can see from the code above we are loading the basic image from...
   · Ok it will be corrected soon
   · My bad...I fixed this yesterday...
   · I have been meaning to get a Captcha image installed on my little application. As...
   · Can i use this code to play around and use it in a wordpress (http://wordpress.org)...
   · Problem to use in Post nukewhen i impliment the captcha on post nuke web then i...
   · You can do what you like with it, although i thought wordpress included a much...
   · By changing this line:$string = substr($md5,0,5);With the following gives you...
   · By changing this line:$string = substr($md5,0,5);With the following gives you...
   · I get a problem that dont show the picture it shows alot of strange text...
   · <?php//Start the session so we can store what the code actually...
   · This was the base of the new captcha I made, except I did things a little...
   · please add this to the headers partheader("Cache-Control: no-cache,...
   · All goes well on a new page but I get this message when I incorporate it in an...
   · I get the same error when I don't start the session above the <html> tags,...
   · The site http://www.trycaptcha.com lets you try a bunch of open source CAPTCHA...
   · This tutorial really helped me out, thanks for the source!
   · Thanks for helpful little tutorial on how to do CAPTCHA! Never had to think about it...

>>> Post your comment now!