Let's say I have some great secret contained in a file smartly named "secret.txt". Here's what I would do:

1. First I'd take "secrets.txt" and compress it with Winrar, encrypted with a password (like "1234" or something a bit harder to guess ;-). The result may be a file aptly named "secrets.rar"

2. Now I find a suitable masking file. Let's say it's a picture of a spy, named "spy.jpg". I put it in the same folder as "secrets.rar", open a command prompt (in Windows: start->run->cmd) and navigate to that folder, then type:

copy /b spy.jpg+secrets.rar "not a spy.jpg"

What this command does is take the first file, stitch the second file right after (keeping everything binary), and save it as the third file. The result is a file named "not a spy.jpg" which will appear to any program (except Winrar and very few others) to be a picture of a spy. Naturally, if you edit the file, the secret information will be lost, but this is true of pretty much any steganographic scheme.


-hz-