When an Image is More than an Image
Steganography is a technique of hiding one type of "information" within another. Since digital information is simply a sequence of bits, some sort of organisation has to be imposed from the outside. This organization, or format, is what gives us our different forms of digital representation: image files (jpg, gif, png), audio (mp3, ogg), video (mov, avi, ogv), and text (txt, odt, doc), etc. Given this agnosticism to content, it is possible to rearrange the bits in certain ways in order to hide messages, or even entire files.
The goal of steganography in the digital domain is to make it appear as if nothing is going on; using encryption will be obvious to any eavesdropper, while using existing formats, slightly modified, ought to not be detected. The idea, then, is to make minuscule changes to an existing file, such as an image or movie, that, when using the right program and, sometimes, correct password, allows the hidden information to be retrieved.
We have uploaded a series of images to Google's Picasa platform, a site that doesn't have artificial filesize limits as with Flickr—something important for our demonstration. Consider, then, the stepic program, and apply it to the images, if you want. See what might be possible in new forms of distribution.
Journal of Journal Performance Studies is a 2009 commission of New Radio and Performing Arts, Inc., (aka Ether-Ore) for its Turbulence web site. It was made possible with funding from the Jerome Foundation.
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