the information hiding homepage -- digital watermarking & steganography :
"Until recently, information hiding techniques received very much less attention from the research community and from industry than cryptography, but this has changed rapidly over the last decade."

The first academic conference on the subject was organised in 1996. It was followed by several other conferences focussing on information hiding as well as watermarking. The fifth international workshop on information hiding was held in Noordwijkerhout (pronounce node-why-cur-how-t) in October 2002.

The main driving force is concern over protecting copyright; as audio, video and other works become available in digital form, it may be that the ease with which perfect copies can be made will lead to large-scale unauthorised copying which will undermine the music, film, book and software publishing industries. There has therefore been significant recent research into ‘watermarking’ (hidden copyright messages) and ‘fingerprinting’ (hidden serial numbers or a set of characteristics that tend to distinguish an object from other similar objects); the idea is that the latter can be used to detect copyright violators and the former to prosecute them.

But there are many other other applications of increasing interest to both the academic and business communities, including anonymous communications, covert channels in computer systems, detection of hidden information, steganography, etc.

http://www.petitcolas.net/fabien/steganography/index.html