Re: CAPTCHA image validation in web form

[Joe Pluta <joepluta@xxxxxxxxxxxxxxxxx>]

Nathan Andelin wrote:
> But there's a 1/7 chance that a bot could pick the right image the first 
> time, and over a large enough number of iterations a smart bot could 
> learn which radio button descriptions were paired with which image 
> files.  Over a large enough number of iterations a bot could esentially 
> download & duplicate your entire image library and cross-reference 
> table.
>   
In this case, you would never use a static name for the image.  There 
are a number of ways to handle it, but one simple way would be to create 
a new symbolic link in the IFS to the image for each request, and then 
send that symbolic link name.  You'd run a regular job to clear out old 
links.

Joe