E-Business
Issue No. 10 - April/May 2003
Secret Messages
by David Twiss
Most of us have heard the stories of the German Enigma code machine used during World War II, and of Bletchly Park and Alan Turing, both instrumental in cracking the Enigma code.
The use of cryptographic codes to scramble a message so it cannot be understood by other than the intended recipient certainly predates the computer, the telephone and even the automobile.
However with the emergence of the Internet and the ubiquity of the PC governments around the world have felt threatened by the increasingly widespread availability of strong cryptographic codes.
It seems that just as the Internet has been of great utility for legitimate business, government and social purposes, it is also proving useful to the less savoury aspects of our world including organised crime and terrorism.
As if the problem of decrypting obviously encrypted communications were not enough to contend with it turns out that cryptography has a cousin. Somewhat less well known than cryptography is the science of steganography.
Steganography and cryptography are closely related concepts. Where cryptography scrambles a message so it cannot be understood, steganography hides a message so it cannot be seen.
A popular, albeit trivial instance of steganography is 'backmasking'.
It has long been observed by some that playing certain pieces of music backwards resulted in a rather different message to the lyrics when played forwards. Perhaps most famous of these so-called 'backmasking' instances is the track by Led Zeplin, Stairway to Heaven. Some people are sure they can hear satanic verses when the song is played backwards. Michael Jackson and the Beatles have all been accused of placing secret messages in their songs.
Personally I struggle to discern anything so sinister or indeed meaningful at all when playing songs backwards. However, more recently it is certainly the case that some people are hiding information inside a variety of files, and for ...
