Visual Cryptography Kit | Hacker News Reader

Visual Cryptography Kit

cl.cam.ac.uk

63 pointssr27 comments

  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?

Result: http://imgur.com/DpcqpMs

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.

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

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

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

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

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