I was interested in coding an app that hides digital markings in media files (audio signal). Anyone looking into this emerging technology at the WP? The technique I would like to employ is called "spread spectrum" in which the markings are spread across frequency domain based on a key. I am no DSP guy (or a real programmer) and was just researching. If someone has interest in this field, please let me know, I might have a future project for you.