Steganography with flickr

This caught my attention for some reason. I guess because steganography is such an unusual word and because the list of uses has been covered so much in the news. I found this article talking about how someone tested to see if there was any kind of filtering on flickr for images containing documents hidden using steganography.

Now steganography is essentially a technique of embedding any file within another file (image/audio) without significantly altering the other file. Let's say for instance you're looking at a pretty picture of a lake. Hidden within that lake image could be a hidden document about foreign policy. In fact one of the more publicly discussed uses of steganography has been by terror groups as a means to covertly trasmit information. There are a number of software tools to both hide and retrieve data from images.

Anyway, the idea of this writer is using flikr as an offsite backup for not only pictures but encrypted documents within the pictures. It's an interesting thought, with the encryption it should be VERY hard to retrieve the data (but not necessarily impossible?) The file size of the test file he came up with was actually SMALLER than the original photo.