patternCaptcha

patternCaptcha works by serving the user with a pattern image and a canvas where he has to re-draw the pattern using his mouse (or touchscreen).

If the pattern is successfully reproduced in the correct order and direction, the action he wanted to make is carried out (form submission, access to a download, page redirection, etc.).

Since everybody is already familiar with Android's famous unlock screen, patternCaptcha uses a similar dotted grid to work.

For plotting out the dots and grids, the HTML 5 canvas element is used. patternCaptcha works on the server-side, while for the client-side patternLock is needed.

Requirements:

• JavaScript enabled on client side
• Node.js
• patternLock
• HTML 5 canvas enabled browser