There are more sophisticated steganograpic tools out there for this purpose; Wikipedia has a good writeup on it: http://en.wikipedia.org/wiki/Steganography http

There are more sophisticated steganograpic tools out there for this purpose; Wikipedia has a good writeup on it: http://en.wikipedia.org/wiki/Steganography http://en.wikipedia.org/wiki/Steganography Several years ago Neils Provos wrote several papers and tools for detecting this content: http://www.citi.umich.edu/u/provos/stego/ http://www.citi.umich.edu/u/provos/stego/