Visual Cryptography Kit

i336_ · on June 11, 2017

  data:text/html,
  <style>img { opacity: 0.5; position: fixed; left: 0; top: 0 }</style>
  <body><img src="https://www.cl.cam.ac.uk/~fms27/vck/share1.gif">
  <img src="https://www.cl.cam.ac.uk/~fms27/vck/share2.gif">

Of course, I did this via the domtools^Wdevtools before experimentally trying the above, which happily works as well.

I think the reason the images loaded was because I was on a data: URI? Or am I misinterpreting CORS?

hackcasual · on June 10, 2017

Result: http://imgur.com/DpcqpMs

Luc · on June 10, 2017

I printed the images onto A4 paper (held in front of a lamp). It's quite fiddly to get them to match. Very fine sub-mm accuracy needed.

moondev · on June 11, 2017

just drag the image on top of the other with your mouse

Luc · on June 11, 2017

The point is that it's much harder with a hardcopy...

grenoire · on June 10, 2017

Not only that, but both sources must be printed at the same aspect ratio and DPI.

devdoomari · on June 11, 2017

isn't this somewhat easy-to-decrypt than OTP? this isn't using some XORs, but 'OR' operations.