A technique for creating a non-graphical pure CSS CAPTCHA is described below.
This is largely by way of a demo of an unusual use for CSS - the CAPTCHA can be solved programmatically without too much difficulty. It is possible to create a simliar CAPTCHA that would be a great deal more robust but I am not sure it is worth the effort. In any case, I would like to have feedback and, should anyone care, code to solve the CAPTCHA.
That's an interesting method
That's an interesting method of generating an visual captcha. Is there any advantage to using the CSS generated area instead of an image?
The next captcha I'm going to implement will be a "honeypot" input field.
Not sure that there are any
Not sure that there are any benefits. For someone on a mobile browser it could be argued tht there is a slight benefit - lower bandwidth to be paid for all the time it is in use means not having to download images might be an attraction. On the other hand the very fact that accesss is not free makes mobile browsing less likely to be a target for fraudsters?
Anyway, I just did this as a fun exercise and as a rather neat demo of just what CSS can do.