The FBI recently reported that spies hid messages on public websites: FBI: Spies Hid Secret Messages on Public Websites. This concept of hiding information is called steganography. Information is visible yet hidden. With this concept, one digital photo can be used to hide another.
After reading about the Russian spies, I felt a need to give steganography a try. I’m sure there are approaches, as well.
- Download the free steganograpahy software available at Steganography 1.0 Build 12.
- Load one bitmap image into Steganography
- Add another image as a data file. This image can have any file format.
- Save the resulting image.
- The hidden image can be recovered with the same program that was used to create it.
It was surprisingly easy. I was able to hide one digital photo in another, see Steganography Test.bmp. Let me know if you are able to view the hidden image in this photo.
Although it is not as interesting, steganography is also used to hide copyright information in digital photos.