A steganography hiding tool

 Steghide is steganography program which hides bits of a data file
 in some of the least significant bits of another file in such a way
 that the existence of the data file is not visible and cannot be proven.
 .
 Steghide is designed to be portable and configurable and features hiding
 data in bmp, wav and au files, blowfish encryption, MD5 hashing of
 passphrases to blowfish keys, and pseudo-random distribution of hidden bits
 in the container data.