Just some thoughts about CAPTCHA

[pedmacedo 0]

I was thinking about CAPTCHA these days... what if someone:

1- gets all of the CAPTCHA images from a site

2- find its answers

3- Store the pixel checksum of each image

Then when he connects to the site, he just needs to make the pixel checksum of the image that appears and check the answer on his database.

But I think this wouldn't work, otherwise any script kiddie could bypass a CAPTCHA system. But why?

[DarkestHour 0]

Captcha systems typically will generate the image on the fly with numerous random variables, making it near impossible to brute force it in such a way. The sheer number of images that would have to be processed to even handle just one type of captcha would make just about anyone squirm.

[SmOke_N 203]

Captcha is there for a reason. It is assumed that if there is a Captcha, that site does not want it automated, which is also assumed it's against their TOS.