Re: CAPTCHA image validation in web form

[Nathan Andelin <nandelin@xxxxxxxxxxxx>]

> From Guillermo Andrades:
> please select the image:
> _ ICE  _ BOAT  _ GIRL  _ THE MOON  _ FLOWERS  _ GUITAR  _ THE SUN

The nice thing about that idea is that a bot with an OCR reader couldn't 
decipher an image of a boat, for example.

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.

Nathan.