Forum OpenACS Q&A: Re: Captchas for the register form

Posted by Matthew Burke on
Two things to point out:

1. I cannot recall where I read this, but one approach I've seen described works roughly as follows:

Use the CSS nodisplay to hide a field on a form and then reject the form if the field is filled in. The idea is that spambots won't see the css and fill the field in. In case a human browser has disabled or doesn't have CSS and actually sees this dummy field, you can label it something like "Email address, but don't actually fill this in"

Anyway you get the idea.

2. One of the Ruby Quizzes ( outlines an approach for "Turing Test" CAPTCHAs. It would be pretty easy to port the idea into Tcl.


Posted by César Clavería on
Both are a pretty interesting and clever approach, thanks for the info.

I have been improving the captcha script a little bit, now it doesnt requires any use of database and the images have moved to a more standard location because it seems this will be integrated to openacs in a not so distant future.