Other ways to create better Captchas

The qualtity of OCR-Software to recognize alphanumeric Captcha characters is getting better and better. That's the reason to find new ways to make Captchas safer too. E.g. Example 10 shows how to use symbols/icons instead of alphanumeric characters.

For the future i'll present other solutions on this website, and i'd be very pleased if someone else would present his/hers ideas.

Example #1

Take 2: Instead of using one Captcha image we take two half images. The upper half image was placed as a background image inside a <div>-Tag, and the lower half image is a normal foreground image (see white dividing line). Result: a Spam-Robot/OCR-Software will only find the foreground image and is unable to recognize any character.

Download: -

Example #2

Click in the opened circle: This captcha is a form button (type="image"). If the button was clicked, the browser sends the actual mouse cursor X/Y-position. The captcha is solved, when the position was inside the opened circle. The advantage of this captcha is, that users don't have to make any keyboard inputs, they only have to click into a random area.. The disadvantage is, that the random area is too small for more than 5-6 circles and a bot could guess the right position. Solution: create a bigger button and/or smaller circles.

Download: example2.zip