|
|
Posted by Jim Moseby on 10/03/96 11:36
> 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
Navigation:
[Reply to this message]
|