To help flog the second edition of Disappearing Cryptography and
encourage a general education in things steganographic, I'm
continuing to roll out Java applets on the book's website. The latest
applet lets you hide information in the noise of an image. That is,
replace the least significant bits of an image with either an ASCII
text message or random data. You can replace anywhere between 1 to
all 8 of the image's bit plane. I think it's amazing how much you can
stuff in an image before it starts to degrade.
This experiment has its problems. Video cards don't always offer
enough precision. You'll get more consistent results if you use a
higher setting on your video card. Also, this system relies upon
24-bit color, a file format that's rarely found in nature. More
sophisticated systems can target compressed images.
Try it here:
http://www.wayner.org/books/discrypt2/bitlevel.php
You can try earlier applets like this one for hiding information in
the order of a list of items:
http://www.wayner.org/books/discrypt2/sorted.php
Or this one for hiding in the voice over to a baseball game:
http://www.wayner.org/texts/mimic/
Source code protected by the GPL available for all of these. Just ask.
You might also be interested in my other new book for people who must
guard sensitive information in their database:
http://www.wayner.org/books/td/
