Visual Cryptography

[Darren Dirt]

now that's a cool result of a pretty simple idea!

http://en.wikipedia.org/wiki/Visual_cryptography



and here's a handy in-the-web-browser tool, after typing in some text (or drawing lines, etc.) it generates the 2 images for you, and you can of course drag one "over" the other in your modern web browsers and see the secret message!

http://www-ti.informatik.uni-tuebingen.de/~borchert/Troja/studdiplchrist/indexEN.php



on that same site, you can actually import in 3 images, and it will use the 1st two images to "hide" the 3rd (I think that's what it does -- it's in German -- see Google Translate text contents) ...

http://www-ti.informatik.uni-tuebingen.de/~borchert/Troja/studdiplchrist/steganographie/

^ the example given on the page before you upload your own gives you the below attached files (0.gif and 1.gif) and if you save img0 and img1 on your PC and then bring them both into MSPaint or similar (with transparency for the "white" pixels) YOU GET THE 3RD IMAGE, you really do! it's actually quite freaky when it works!