RE: [PHP] Graphically displayed number to confirm user is a human

> PHP General List, > > This is something I tried to find on Google, but I'm > hindered by not > knowing the proper terminology. > On many sites that have contact or registration forms, > they have a > small image file with a randomly generated number shown in a distorted > graphical fashion that is hard for a computer to scan and read. > The purpose is that the site visitor has to type in the > numbers into a > field, in order to verify that it is, in fact, a human filling out the > form. > First, is there a term for these kinds of images, or > that kind of > verification system? What would be the best search terms to look for > source scripts? > Second, can anyone recommend a resource for that kind > of PHP script. If > I really worked at it, I could probably write the script to generate a > small PNG image with a random number in it. But I haven't the faintest > clue how to distort it so it's only legible to humans, nor how to > correlate the image with a number that a user inputs into a > form field. Google for "CAPTCHA", and you'll be amazed at the number of hits! JM