captcha

Captcha based on image rotation implemented somewhere?

Having read google's paper from 09 [1] about captchas based on image rotation I wonder if they are implemented somewhere. Did anybody see an actual system which uses them? (I haven't created a google account in a while, but I think they still use "normal" captchas) http://research.google.com/pubs/archive/35157.pdf ...

Relevant literature about captchas

So I'm wondering what are the relevant publications one has to read in order to understand how some CAPTCHAs are hacked and how they can made more difficult to recognize by a machine. Of course there is basic image processing literature, but besides that? I'm also only interested in recent publication. For example the first step that on...

Checkbox as alternative to captcha?

Does a checbox provide an alternative to using captcha on website? I am thinking i i need to use captcha for user signup. Instead if i put a checkbox for the terms like "By clicking here I agree...." can that solve the bots issues or is captcha required in addition to the checkbox? ...

Javascript - Load an image onclick

OK, I'm actually calling some java middleware that returns a captcha image. The captcha image loads in the page on page load simply with: <a href="#" id="ci"><img id="stickyImg" src="stickyImg" /></a> I want to reload the captcha image onclick of the current captcha image. I've tried a few things but am not getting anything working. ...

captcha image coming back a binary data? How to display this?

I am retrieving a captcha image from the Java based package "SimpleCaptcha" On the front end I just put the following in my page and I get a captcha image: <img src="stickyImg" /> I want to reload this captcha image onclick using javascript. I tried: $("#theclickhandler").click(function(){ $("#stickyImg").load('stickyImg', fu...